Research OrcID: 0000-0001-8946-1847
Scopus ID: 57201445170

2023

  • [DOI] S. Cuccurullo, F. Maspero, O. Koplak, G. Pavese, E. Albisetti, M. Cantoni, and R. Bertacco, “Impact of minor hysteresis loops in integrated inductors with ferromagnetic films,” Applied Physics Letters, vol. 122, iss. 11, p. 113503, 2023.
    [Bibtex] 
    @article{Cuccurullo2023,
abstract = {Integration of inductors on silicon chips is becoming more and more relevant for monolithic electronic applications. In this Letter, we investigate the impact of minor hysteresis loops in an integrated inductor with spiral geometry sandwiched between two soft magnetic layers made of MoNiFe/Cr multilayers. Despite high magnetic susceptibility and low coercivity of optimized multilayers, we find that the inductance is strongly dependent on the AC voltage applied to the device, showing a bell-shaped behavior. Comparing the measured inductance with magneto-optical Kerr effect and vibrating sample magnetometry measurements, we show that the low-signal behavior is limited by domain wall pinning/depinning, which determine the effective susceptibility associated with minor hysteresis loops driven by the applied AC voltage.},
author = {Cuccurullo, S. and Maspero, F. and Koplak, O. and Pavese, G. and Albisetti, E. and Cantoni, M. and Bertacco, R.},
doi = {10.1063/5.0127390},
journal = {Applied Physics Letters},
number = {11},
pages = {113503},
title = {{Impact of minor hysteresis loops in integrated inductors with ferromagnetic films}},
url = {https://pubs.aip.org/aip/apl/article/122/11/113503/2881063/Impact-of-minor-hysteresis-loops-in-integrated},
volume = {122},
year = {2023}
}

2022

  • [DOI] A. Kumar, S. A. Mirshokraee, A. Lamperti, M. Cantoni, M. Longo, and C. Wiemer, “Interface Analysis of MOCVD Grown GeTe/Sb2Te3 and Ge-Rich Ge-Sb-Te/Sb2Te3 Core-Shell Nanowires,” Nanomaterials, vol. 12, iss. 10, 2022.
    [Bibtex] 
    @article{nano12101623,
abstract = {Controlling material thickness and element interdiffusion at the interface is crucial for many applications of core-shell nanowires. Herein, we report the thickness-controlled and conformal growth of a Sb2Te3 shell over GeTe and Ge-rich Ge-Sb-Te core nanowires synthesized via metal-organic chemical vapor deposition (MOCVD), catalyzed by the Vapor–Liquid–Solid (VLS) mechanism. The thickness of the Sb2Te3 shell could be adjusted by controlling the growth time without altering the nanowire morphology. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were employed to examine the surface morphology and the structure of the nanowires. The study aims to investigate the interdiffusion, intactness, as well as the oxidation state of the core-shell nanowires. Angle-resolved X-ray photoelectron spectroscopy (XPS) was applied to investigate the surface chemistry of the nanowires. No elemental interdiffusion between the GeTe, Ge-rich Ge-Sb-Te cores, and Sb2Te3 shell of the nanowires was revealed. Chemical bonding between the core and the shell was observed.},
author = {Kumar, Arun and Mirshokraee, Seyed Ariana and Lamperti, Alessio and Cantoni, Matteo and Longo, Massimo and Wiemer, Claudia},
doi = {10.3390/nano12101623},
issn = {2079-4991},
journal = {Nanomaterials},
number = {10},
title = {{Interface Analysis of MOCVD Grown GeTe/Sb2Te3 and Ge-Rich Ge-Sb-Te/Sb2Te3 Core-Shell Nanowires}},
url = {https://www.mdpi.com/2079-4991/12/10/1623},
volume = {12},
year = {2022}
}

2021

  • [DOI] S. Varotto, L. Nessi, S. Cecchi, J. S{l}awińska, P. Noël, S. Petrò, F. Fagiani, A. Novati, M. Cantoni, D. Petti, E. Albisetti, M. Costa, R. Calarco, M. {Buongiorno Nardelli}, M. Bibes, S. Picozzi, J. -P. Attané, L. Vila, R. Bertacco, and C. Rinaldi, “Room-temperature ferroelectric switching of spin-to-charge conversion in germanium telluride,” Nature Electronics, vol. 4, iss. 10, p. 740–747, 2021.
    [Bibtex] 
    @article{Varotto2021740,
author = {Varotto, S and Nessi, L and Cecchi, S and S{\l}awi{\'{n}}ska, J and No{\"{e}}l, P and Petr{\`{o}}, S and Fagiani, F and Novati, A and Cantoni, M and Petti, D and Albisetti, E and Costa, M and Calarco, R and {Buongiorno Nardelli}, M and Bibes, M and Picozzi, S and Attan{\'{e}}, J.-P. and Vila, L and Bertacco, R and Rinaldi, C},
doi = {10.1038/s41928-021-00653-2},
journal = {Nature Electronics},
number = {10},
pages = {740--747},
title = {{Room-temperature ferroelectric switching of spin-to-charge conversion in germanium telluride}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85117200899&doi=10.1038%2Fs41928-021-00653-2&partnerID=40&md5=2f0625896fd2c8e99778126c47a26130},
volume = {4},
year = {2021}
}
  • [DOI] M. Giacometti, F. Milesi, P. L. Coppadoro, A. Rizzo, F. Fagiani, C. Rinaldi, M. Cantoni, D. Petti, E. Albisetti, M. Sampietro, M. Ciardo, G. Siciliano, P. Alano, B. Lemen, J. Bombe, M. T. {Nwaha Toukam}, P. F. Tina, M. R. Gismondo, M. Corbellino, R. Grande, G. B. Fiore, G. Ferrari, S. Antinori, and R. Bertacco, “A Lab-On-chip Tool for Rapid, Quantitative, and Stage-selective Diagnosis of Malaria,” Advanced Science, vol. 8, iss. 14, 2021.
    [Bibtex] 
    @article{Giacometti2021,
author = {Giacometti, M and Milesi, F and Coppadoro, P L and Rizzo, A and Fagiani, F and Rinaldi, C and Cantoni, M and Petti, D and Albisetti, E and Sampietro, M and Ciardo, M and Siciliano, G and Alano, P and Lemen, B and Bombe, J and {Nwaha Toukam}, M T and Tina, P F and Gismondo, M R and Corbellino, M and Grande, R and Fiore, G B and Ferrari, G and Antinori, S and Bertacco, R},
doi = {10.1002/advs.202004101},
journal = {Advanced Science},
number = {14},
title = {{A Lab-On-chip Tool for Rapid, Quantitative, and Stage-selective Diagnosis of Malaria}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105873696&doi=10.1002%2Fadvs.202004101&partnerID=40&md5=93030bb16052fc7078f9c11adfb761d7},
volume = {8},
year = {2021}
}
  • [DOI] M. Asa, C. Rinaldi, L. Nessi, D. Chrastina, D. Petti, E. Albisetti, R. Bertacco, and M. Cantoni, “Epitaxy and controlled oxidation of chromium ultrathin films on ferroelectric BaTiO3 templates,” Journal of Crystal Growth, vol. 558, 2021.
    [Bibtex] 
    @article{Asa2021,
abstract = {{\textcopyright} 2020 Elsevier B.V. Interfaces play a crucial role in the study of novel phenomena emerging at heterostructures comprising metals and functional oxides. In this work, we consider Cr/BaTiO3 heterostructures grown on Nb:SrTiO3 (0 0 1) substrates. Chromium thin films with 2 nm nominal thickness are deposited by molecular beam epitaxy on the BaTiO3 layer, and subsequently annealed in vacuum at temperatures ranging from 800 K to 970 K, and finally exposed to 10−7 torr of molecular oxygen for 300 s. Highly ordered films are obtained for each of this condition, ranging from metallic Cr to insulating Cr2O3 with tetragonal structure. Quite unexpectedly, an intermediate – fully ordered – case exists, with the co-presence of Cr and Cr2O3 compounds, each one with its proper crystal orientation. These results show the opportunity of controlling the metal/oxide state of crystalline Cr films grown onto the ferroelectric template BaTiO3/Nb:SrTiO3.},
author = {Asa, M. and Rinaldi, C. and Nessi, L. and Chrastina, D. and Petti, D. and Albisetti, E. and Bertacco, R. and Cantoni, M.},
doi = {10.1016/j.jcrysgro.2020.126012},
issn = {00220248},
journal = {Journal of Crystal Growth},
keywords = {A1. Crystal structure,A1. Low dimensional structures,A2. Single crystal growth,A3. Molecular beam epitaxy,B1. Metals,B1. Oxides},
title = {{Epitaxy and controlled oxidation of chromium ultrathin films on ferroelectric BaTiO3 templates}},
volume = {558},
year = {2021}
}

2020

  • [DOI] M. Ghirardello, V. Otero, D. Comelli, L. Toniolo, D. Dellasega, L. Nessi, M. Cantoni, G. Valentini, A. Nevin, and M. J. Melo, “An investigation into the synthesis of cadmium sulfide pigments for a better understanding of their reactivity in artworks,” Dyes and Pigments, 2020.
    [Bibtex] 
    @article{Ghirardello2020,
author = {Ghirardello, M and Otero, V and Comelli, D and Toniolo, L and Dellasega, D and Nessi, L and Cantoni, M and Valentini, G and Nevin, A and Melo, M J},
doi = {10.1016/j.dyepig.2020.108998},
journal = {Dyes and Pigments},
title = {{An investigation into the synthesis of cadmium sulfide pigments for a better understanding of their reactivity in artworks}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096436460&doi=10.1016%2Fj.dyepig.2020.108998&partnerID=40&md5=18ff13f8e5fd20a49c1ab4d80d427aac},
year = {2020}
}
  • [DOI] F. Motti, G. Vinai, V. Bonanni, V. Polewczyk, P. Mantegazza, T. Forrest, F. MacCherozzi, S. Benedetti, C. Rinaldi, M. Cantoni, D. Cassese, S. Prato, S. S. Dhesi, G. Rossi, G. Panaccione, and P. Torelli, “Interplay between morphology and magnetoelectric coupling in Fe/PMN-PT multiferroic heterostructures studied by microscopy techniques,” Physical Review Materials, vol. 4, iss. 11, 2020.
    [Bibtex] 
    @article{Motti2020,
author = {Motti, F and Vinai, G and Bonanni, V and Polewczyk, V and Mantegazza, P and Forrest, T and MacCherozzi, F and Benedetti, S and Rinaldi, C and Cantoni, M and Cassese, D and Prato, S and Dhesi, S S and Rossi, G and Panaccione, G and Torelli, P},
doi = {10.1103/PhysRevMaterials.4.114418},
journal = {Physical Review Materials},
number = {11},
title = {{Interplay between morphology and magnetoelectric coupling in Fe/PMN-PT multiferroic heterostructures studied by microscopy techniques}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097141886&doi=10.1103%2FPhysRevMaterials.4.114418&partnerID=40&md5=08b702b100e2febfe0d9938c870e1df0},
volume = {4},
year = {2020}
}
  • [DOI] M. Asa, C. Autieri, R. Pazzocco, C. Rinaldi, W. Brzezicki, A. Stroppa, M. Cuoco, G. Varvaro, S. Picozzi, and M. Cantoni, “Anomalous Hall effect in antiferromagnetic/nonmagnetic interfaces,” Phys. Rev. Research, vol. 2, iss. 4, p. 43394, 2020.
    [Bibtex] 
    @article{PhysRevResearch.2.043394,
author = {Asa, M and Autieri, C and Pazzocco, R and Rinaldi, C and Brzezicki, W and Stroppa, A and Cuoco, M and Varvaro, G and Picozzi, S and Cantoni, M},
doi = {10.1103/PhysRevResearch.2.043394},
journal = {Phys. Rev. Research},
number = {4},
pages = {43394},
publisher = {American Physical Society},
title = {{Anomalous Hall effect in antiferromagnetic/nonmagnetic interfaces}},
url = {https://link.aps.org/doi/10.1103/PhysRevResearch.2.043394},
volume = {2},
year = {2020}
}
  • [DOI] E. Longo, C. Wiemer, M. Belli, R. Cecchini, M. Longo, M. Cantoni, C. Rinaldi, M. D. Overbeek, C. H. Winter, G. Gubbiotti, G. Tallarida, M. Fanciulli, and R. Mantovan, “Ferromagnetic resonance of Co thin films grown by atomic layer deposition on the Sb2Te3 topological insulator,” Journal of Magnetism and Magnetic Materials, vol. 509, 2020.
    [Bibtex] 
    @article{Longo2020,
abstract = {{\textcopyright} 2020 Elsevier B.V. Interfacing ferromagnetic materials with topological insulators is an intriguing strategy in order to enhance spin-to-charge conversion mechanisms, paving the way toward highly efficient spin-based electronic devices. In particular, the use of large-scale deposition techniques is demanding for a sustainable and cost-effective industrial technology transfer. In this work, we study the magnetic properties of the Co/Sb2Te3 heterostructure, where the ferromagnetic Co layer is deposited by atomic layer deposition on top of the Sb2Te3 topological insulator, which is grown by metal organic chemical vapor deposition. In particular, broadband ferromagnetic resonance is employed to characterize the Co/Sb2Te3 system and the reference Co/Pt heterostructure. For Co/Sb2Te3, we extract an effective magnetic anisotropy constant [Formula presented], which is an order of magnitude higher than in Co/Pt [Formula presented]. The large difference in the Keff values observed in Co/Sb2Te3 and Co/Pt is explained in terms of the different Co crystalline structures achieved on top of Sb2Te3 and Pt, respectively. Interestingly, the Co/Sb2Te3 system displays a relatively large Gilbert damping constant ($\alpha$ = 0.095), which we suggest as possibly due to spin pumping from the Co layer into the Sb2Te3 topological insulator.},
author = {Longo, E. and Wiemer, C. and Belli, M. and Cecchini, R. and Longo, M. and Cantoni, M. and Rinaldi, C. and Overbeek, M.D. and Winter, C.H. and Gubbiotti, G. and Tallarida, G. and Fanciulli, M. and Mantovan, R.},
doi = {10.1016/j.jmmm.2020.166885},
issn = {03048853},
journal = {Journal of Magnetism and Magnetic Materials},
title = {{Ferromagnetic resonance of Co thin films grown by atomic layer deposition on the Sb2Te3 topological insulator}},
volume = {509},
year = {2020}
}
  • [DOI] E. Albisetti, S. Tacchi, R. Silvani, G. Scaramuzzi, S. Finizio, S. Wintz, C. Rinaldi, M. Cantoni, J. Raabe, G. Carlotti, R. Bertacco, E. Riedo, and D. Petti, “Optically Inspired Nanomagnonics with Nonreciprocal Spin Waves in Synthetic Antiferromagnets,” Advanced Materials, vol. 32, iss. 9, 2020.
    [Bibtex] 
    @article{Albisetti2020,
abstract = {{\textcopyright} 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Integrated optically inspired wave-based processing is envisioned to outperform digital architectures in specific tasks, such as image processing and speech recognition. In this view, spin waves represent a promising route due to their nanoscale wavelength in the gigahertz frequency range and rich phenomenology. Here, a versatile, optically inspired platform using spin waves is realized, demonstrating the wavefront engineering, focusing, and robust interference of spin waves with nanoscale wavelength. In particular, magnonic nanoantennas based on tailored spin textures are used for launching spatially shaped coherent wavefronts, diffraction-limited spin-wave beams, and generating robust multi-beam interference patterns, which spatially extend for several times the spin-wave wavelength. Furthermore, it is shown that intriguing features, such as resilience to back reflection, naturally arise from the spin-wave nonreciprocity in synthetic antiferromagnets, preserving the high quality of the interference patterns from spurious counterpropagating modes. This work represents a fundamental step toward the realization of nanoscale optically inspired devices based on spin waves.},
author = {Albisetti, E. and Tacchi, S. and Silvani, R. and Scaramuzzi, G. and Finizio, S. and Wintz, S. and Rinaldi, C. and Cantoni, M. and Raabe, J. and Carlotti, G. and Bertacco, R. and Riedo, E. and Petti, D.},
doi = {10.1002/adma.201906439},
issn = {15214095},
journal = {Advanced Materials},
keywords = {nanomagnonics,scanning probe lithography,scanning transmission X-ray microscopy,spin textures,spin waves,synthetic antiferromagnet},
number = {9},
title = {{Optically Inspired Nanomagnonics with Nonreciprocal Spin Waves in Synthetic Antiferromagnets}},
volume = {32},
year = {2020}
}
  • [DOI] E. Longo, C. Wiemer, R. Cecchini, M. Longo, A. Lamperti, A. Khanas, A. Zenkevich, M. Cantoni, C. Rinaldi, M. Fanciulli, and R. Mantovan, “Fe/Sb2Te3 Interface Reconstruction through Mild Thermal Annealing,” Advanced Materials Interfaces, 2020.
    [Bibtex] 
    @article{Longo2020a,
abstract = {{\textcopyright} 2020 Wiley-VCH GmbH When coupled with ferromagnetic layers (FM), topological insulators (TI) are expected to boost the charge-to-spin conversion efficiency across the FM/TI interface. In this context, a thorough control and optimization of the FM/TI interface quality are requested. Here, the evolution of the chemical, structural, and magnetic properties of the Fe/Sb2Te3 heterostructure is presented as a function of a rapid mild thermal annealing conducted on the Sb2Te3-TI (up to 200 °C). While the bilayer is not subjected to any thermal treatment upon Fe deposition, the annealing of Sb2Te3 markedly improves its crystalline quality, leading to an increase in the fraction of ferromagnetic Fe atoms at the buried Fe/Sb2Te3 interface and a slight lowering of the magnetic coercivity of the Fe layer. The method is an efficient tool to clean up the Fe/Sb2Te3 interface, which may be extended to different FM/TI heterostructures. Simultaneously to the interface reconstruction, a constant ≈20% fraction of FeTe develops at the interface. Since FeTe can display superconductivity, the Fe/Sb2Te3 system could have potentialities for exploiting phenomena at the edge of magnetism, superconductivity and topology.},
author = {Longo, E. and Wiemer, C. and Cecchini, R. and Longo, M. and Lamperti, A. and Khanas, A. and Zenkevich, A. and Cantoni, M. and Rinaldi, C. and Fanciulli, M. and Mantovan, R.},
doi = {10.1002/admi.202000905},
issn = {21967350},
journal = {Advanced Materials Interfaces},
keywords = {ferromagnetism,spintronics,topological insulators},
title = {{Fe/Sb2Te3 Interface Reconstruction through Mild Thermal Annealing}},
year = {2020}
}
  • [DOI] F. A. Memon, F. Morichetti, M. Cantoni, C. Somaschini, M. Asa, R. Bertacco, B. S. Chowdhry, and A. Melloni, “Silicon Oxycarbide Platform for Integrated Photonics,” Journal of Lightwave Technology, vol. 38, iss. 4, 2020.
    [Bibtex] 
    @article{Memon2020,
abstract = {{\textcopyright} 1983-2012 IEEE. In this article we present silicon oxycarbide (SiOC) as a potential dielectric platform for integrated photonic applications. By controlling the amount of carbon and oxygen in the composition of SiOC films, which in this work are deposited by using a reactive RF magnetron sputtering process, the refractive index of the material can be widely tuned from less than that of silica 1.40 to almost that of silicon carbide (3.0), while keeping high transparency in the near-infrared wavelength range. An in-depth analysis of the structural, morphological and optical properties of the deposited SiOC thin films is reported, pointing out the relationship between the change in the film composition and the tuneability of the refractive index. Single mode optical waveguides with a refractive index contrast of up to 28% and propagation loss as low as 2 dB/cm at 1550 nm are demonstrated. An integrated Mach-Zehnder interferometer is presented as a first example of PIC realized on high refractive index SiOC platform. Results show that SiOC is a promising alternative to conventional dielectric platforms for the realization of PICs.},
author = {Memon, F.A. and Morichetti, F. and Cantoni, M. and Somaschini, C. and Asa, M. and Bertacco, R. and Chowdhry, B.S. and Melloni, A.},
doi = {10.1109/JLT.2019.2948999},
issn = {15582213},
journal = {Journal of Lightwave Technology},
keywords = {Integrated optics,optical materials,optical waveguides,silicon oxycarbide},
number = {4},
title = {{Silicon Oxycarbide Platform for Integrated Photonics}},
volume = {38},
year = {2020}
}
  • [DOI] C. Rinaldi, M. Asa, D. Chrastina, J. L. Hart, M. L. Taheri, I. Pallecchi, D. Marré, and M. Cantoni, “Study and optimization of epitaxial films of Cr and Pt/Cr bilayers on MgO,” Journal of Physics D: Applied Physics, vol. 53, iss. 10, 2020.
    [Bibtex] 
    @article{Rinaldi2020,
abstract = {{\textcopyright} 2019 IOP Publishing Ltd. We report a systematic study of the fabrication and chemical and structural characterization of epitaxial Cr films and Pt/Cr bilayers on MgO substrates. Cr films of different thicknesses were grown by molecular beam epitaxy at 373 K and then post-annealed at different temperatures. These films are chemically stable, present a well-ordered tetragonal structure, with only a low degree of oxidation distributed throughout the films. The lattice parameter can be finely tuned by varying the film thickness and the post-annealing temperature, as the elastic energy is progressively relaxed by edge dislocations, so that the film can approach the structural and electrical properties of bulk chromium. Moreover, the chemical and structural properties of Cr are not affected by a Pt capping layer, which grows in a well-ordered Pt[1 1 0]||Cr[1 0 0] orientation, holding potential for applications in recently proposed Pt/Cr-based antiferromagnet spintronics and for the realization of epitaxial Pt films on MgO by using a thin buffer layer of chromium.},
author = {Rinaldi, C. and Asa, M. and Chrastina, D. and Hart, J.L. and Taheri, M.L. and Pallecchi, I. and Marr{\'{e}}, D. and Cantoni, M.},
doi = {10.1088/1361-6463/ab6148},
issn = {13616463},
journal = {Journal of Physics D: Applied Physics},
keywords = {Chromium,Epitaxy,Spectroscopy,Strain,Transport},
number = {10},
title = {{Study and optimization of epitaxial films of Cr and Pt/Cr bilayers on MgO}},
volume = {53},
year = {2020}
}
  • [DOI] F. Motti, C. Martella, S. Vangelista, A. Lamperti, M. Cantoni, A. Molle, and R. Mantovan, “Growth of 2D-molybdenum disulfide on top of magnetite and iron by chemical methods,” Thin Solid Films, vol. 701, 2020.
    [Bibtex] 
    @article{Motti2020a,
abstract = {{\textcopyright} 2020 Elsevier B.V. Systems based on the combination of ferromagnetic (FM) thin films and two-dimensional (2D) transition metal dichalcogenides are currently of high interest in the context of spintronic devices. Here, we report on the fabrication of MoS2/(Fe3O4, Fe) heterojunctions by using chemical-based methods. FM thin films have been initially synthesized on top of Si/SiO2 substrates by chemical vapour deposition. The 2D-MoS2 nanosheets have been grown on top of the FM layers by following the sulfurization of a solid film precursor of molybdenum oxide evaporated at the FMs surface. A comprehensive structural, chemical, morphological and magnetic characterization has been carried out at each step of the process. Several bottlenecks in the fabrication of MoS2/(Fe3O4, Fe) systems have been evidenced, the most critical being the sulfurization process, in which we detect a pronounced tendency of S to react with the underlying FM layers. Our results could explain the limited functionalities often observed so far in spintronic devices based on 2D transition metal dichalcogenides, prompting some limits for their inclusion into practical devices.},
author = {Motti, F. and Martella, C. and Vangelista, S. and Lamperti, A. and Cantoni, M. and Molle, A. and Mantovan, R.},
doi = {10.1016/j.tsf.2020.137943},
issn = {00406090},
journal = {Thin Solid Films},
keywords = {Chemical vapour deposition,Ferromagnetism,Heterostructure,MoS 2,Spintronics,Transition metal dichalcogenides},
title = {{Growth of 2D-molybdenum disulfide on top of magnetite and iron by chemical methods}},
volume = {701},
year = {2020}
}
  • [DOI] M. Asa, C. Rinaldi, R. Pazzocco, D. Petti, E. Albisetti, R. Bertacco, and M. Cantoni, “Electrical readout of the antiferromagnetic state of IrMn through anomalous Hall effect,” Journal of Applied Physics, vol. 128, iss. 5, 2020.
    [Bibtex] 
    @article{Asa2020,
abstract = {{\textcopyright} 2020 Author(s). We report the electrical detection of the antiferromagnetic state of IrMn through anomalous Hall measurements in Ta/IrMn heterostructures. The magnetic state is set in the antiferromagnet through field cooling and detected electrically by transverse resistance measurements in Hall bar structures without the need for any ferromagnetic layer. The amplitude of the signal increases with the magnetic field applied during the cooling and is enhanced by the proximal interface with a Ta layer. From the temperature dependence of the effect and the comparison between Ta/IrMn and Ru/IrMn interfaces, we propose an explanation of such readouts based on the simultaneous occurrence of spin-Hall magnetoresistance and magnetic proximity in Ta. These findings highlight how interface effects could be generally employed for the investigation of antiferromagnetic materials as well as for the electrical readout of the antiferromagnetic state.},
author = {Asa, M. and Rinaldi, C. and Pazzocco, R. and Petti, D. and Albisetti, E. and Bertacco, R. and Cantoni, M.},
doi = {10.1063/5.0009553},
issn = {10897550},
journal = {Journal of Applied Physics},
number = {5},
title = {{Electrical readout of the antiferromagnetic state of IrMn through anomalous Hall effect}},
volume = {128},
year = {2020}
}
  • [DOI] E. Albisetti, G. Scaramuzzi, C. Rinaldi, M. Cantoni, R. Bertacco, and D. Petti, “Temperature dependence of the magnetic properties of IrMn/CoFeB/Ru/CoFeB exchange biased synthetic antiferromagnets,” Materials, vol. 13, iss. 2, 2020.
    [Bibtex] 
    @article{Albisetti2020a,
abstract = {{\textcopyright} 2020 by the authors. Synthetic antiferromagnets (SAF) are widely used for a plethora of applications among which data storage, computing, and in the emerging field of magnonics. In this framework, controlling the magnetic properties of SAFs via localized thermal treatments represents a promising route for building novel magnonic materials. In this paper, we study via vibration sample magnetometry the temperature dependence of the magnetic properties of sputtered exchange bias SAFs grown via magnetron sputtering varying the ferromagnetic layers and spacer thickness. Interestingly, we observe a strong, reversible modulation of the exchange field, saturation field, and coupling strength upon heating up to 250 °C. These results suggest that exchange bias SAFs represent promising systems for developing novel artificial magnetic nanomaterials via localized thermal treatment.},
author = {Albisetti, E. and Scaramuzzi, G. and Rinaldi, C. and Cantoni, M. and Bertacco, R. and Petti, D.},
doi = {10.3390/ma13020387},
issn = {19961944},
journal = {Materials},
keywords = {CoFeB,Exchange bias,Interlayer exchange coupling,Magnetron sputtering,Synthetic antiferromagnet,Thermally assisted magnetic scanning probe lithogr,Vibrating sample magnetometry},
number = {2},
title = {{Temperature dependence of the magnetic properties of IrMn/CoFeB/Ru/CoFeB exchange biased synthetic antiferromagnets}},
volume = {13},
year = {2020}
}

2019

  • M. Asa, C. Autieri, R. Pazzocco, C. Rinaldi, W. Brzezicki, A. Stroppa, M. Cuoco, S. Picozzi, and M. Cantoni, Anomalous Hall effect in antiferromagnetic/non-magnetic interfaces, 2019.
    [Bibtex] 
    @misc{Asa2019,
abstract = {Copyright {\textcopyright} 2019, arXiv, All rights reserved. We report a combined theoretical and experimental investigation of magnetic proximity and Hall transport in Pt/Cr bilayers. Density functional theory indicates that an interfacial magnetization can be induced in the Pt layer and a strong magnetocrystalline anisotropy with an easy axis out of plane arises in the antiferromagnet. A signal ascribed to the anomalous Hall effect is detected and associated to the interface between Pt and Cr layers. We show that this effect originates from the combination of proximity-induced magnetization and a nontrivial topology of the band structure at the interface.},
author = {Asa, M. and Autieri, C. and Pazzocco, R. and Rinaldi, C. and Brzezicki, W. and Stroppa, A. and Cuoco, M. and Picozzi, S. and Cantoni, M.},
booktitle = {arXiv},
title = {{Anomalous Hall effect in antiferromagnetic/non-magnetic interfaces}},
year = {2019}
}
  • [DOI] G. Vinai, F. Motti, V. Bonanni, A. Y. Petrov, S. Benedetti, C. Rinaldi, M. Stella, D. Cassese, S. Prato, M. Cantoni, G. Rossi, G. Panaccione, and P. Torelli, “Reversible Modification of Ferromagnetism through Electrically Controlled Morphology,” Advanced Electronic Materials, vol. 5, iss. 7, 2019.
    [Bibtex] 
    @article{Vinai2019,
abstract = {{\textcopyright} 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Converse magnetoelectric coupling in artificial multiferroics is generally modeled through three possible mechanisms: charge transfer, strain mediated effects or ion migration. Here the role played by electrically controlled morphological modifications on the ferromagnetic response of a multiferroic heterostructure, specifically FexMn1−x ferromagnetic films on piezoferroelectric PMN-PT [001] substrates, is discussed. The substrates present, in correspondence to electrical switching, fully reversible morphological changes at the surface, to which correspond reproducible modifications of the ferromagnetic response of the FexMn1−x films. Topographic analysis by atomic force microscopy shows the formation of surface cracks (up to 100 nm in height) upon application of a sufficiently high positive electric field (up to 6 kV cm−1). The cracks disappear after application of negative electric field of the same magnitude. Correspondingly, in operando X-ray magnetic circular dichroic spectroscopy at Fe edge in FexMn1−x layers and micro-MOKE measurements show local variations in the intensity of the dichroic signal and in the magnetic anisotropy as a function of the electrically driven morphological state. This morphologic parameter, rarely explored in literature, directly affects the ferromagnetic response of the system. Its proof of electrically reversible modification of the magnetic response adds a new possibility in the design of electrically controlled magnetic devices.},
author = {Vinai, G. and Motti, F. and Bonanni, V. and Petrov, A.Y. and Benedetti, S. and Rinaldi, C. and Stella, M. and Cassese, D. and Prato, S. and Cantoni, M. and Rossi, G. and Panaccione, G. and Torelli, P.},
doi = {10.1002/aelm.201900150},
issn = {2199160X},
journal = {Advanced Electronic Materials},
keywords = {electric-field control,ferroelectrics and multiferroics,information storage,morphological effects,multiferroic heterostructure},
number = {7},
title = {{Reversible Modification of Ferromagnetism through Electrically Controlled Morphology}},
volume = {5},
year = {2019}
}
  • [DOI] M. Asa, C. Autieri, C. Barone, C. Mauro, S. Picozzi, S. Pagano, and M. Cantoni, “Detecting antiferromagnetism in tetragonal C r2 O3 by electrical measurements,” Physical Review B, vol. 100, iss. 17, 2019.
    [Bibtex] 
    @article{Asa2019a,
abstract = {{\textcopyright} 2019 American Physical Society. The tetragonal phase of chromium (III) oxide, although unstable in the bulk, can be synthesized in epitaxial heterostructures. Theoretical investigation by density-functional theory predicts an antiferromagnetic ground state for this compound. We demonstrate experimentally antiferromagnetism up to 40 K in ultrathin films of t-Cr2O3 by electrical measurements exploiting interface effect within a neighboring ultrathin Pt layer. We show that magnetotransport in Pt is affected by both spin-Hall magnetoresistance and magnetic proximity effect while we exclude any role of magnetism for the lowerature resistance anomaly observed in Pt.},
author = {Asa, M. and Autieri, C. and Barone, C. and Mauro, C. and Picozzi, S. and Pagano, S. and Cantoni, M.},
doi = {10.1103/PhysRevB.100.174423},
issn = {24699969},
journal = {Physical Review B},
number = {17},
title = {{Detecting antiferromagnetism in tetragonal C r2 O3 by electrical measurements}},
volume = {100},
year = {2019}
}

2018

  • [DOI] M. Veis, J. Minár, G. Steciuk, L. Palatinus, C. Rinaldi, M. Cantoni, D. Kriegner, K. K. Tikuišis, J. Hamrle, M. Zahradník, R. Antoš, J. Železný, L. Šmejkal, X. Marti, P. Wadley, R. P. Campion, C. Frontera, K. Uhlířová, T. Duchoň, P. KuŽel, V. Novák, T. Jungwirth, and K. Výborný, “Band structure of CuMnAs probed by optical and photoemission spectroscopy,” Physical Review B, vol. 97, iss. 12, 2018.
    [Bibtex] 
    @article{Veis2018,
abstract = {{\textcopyright} 2018 American Physical Society. The tetragonal phase of CuMnAs progressively appears as one of the key materials for antiferromagnetic spintronics due to efficient current-induced spin-torques whose existence can be directly inferred from crystal symmetry. Theoretical understanding of spintronic phenomena in this material, however, relies on the detailed knowledge of electronic structure (band structure and corresponding wave functions) which has so far been tested only to a limited extent. We show that AC permittivity (obtained from ellipsometry) and UV photoelectron spectra agree with density functional calculations. Together with the x-ray diffraction and precession electron diffraction tomography, our analysis confirms recent theoretical claim [Phys. Rev. B 96, 094406 (2017)2469-995010.1103/PhysRevB.96.094406] that copper atoms occupy lattice positions in the basal plane of the tetragonal unit cell.},
author = {Veis, M. and Min{\'{a}}r, J. and Steciuk, G. and Palatinus, L. and Rinaldi, C. and Cantoni, M. and Kriegner, D. and Tikui{\v{s}}is, K.K. and Hamrle, J. and Zahradn{\'{i}}k, M. and Anto{\v{s}}, R. and {\v{Z}}elezn{\'{y}}, J. and {\v{S}}mejkal, L. and Marti, X. and Wadley, P. and Campion, R.P. and Frontera, C. and Uhl{\'{i}}řov{\'{a}}, K. and Duchoň, T. and Ku{\v{Z}}el, P. and Nov{\'{a}}k, V. and Jungwirth, T. and V{\'{y}}born{\'{y}}, K.},
doi = {10.1103/PhysRevB.97.125109},
issn = {24699969},
journal = {Physical Review B},
number = {12},
title = {{Band structure of CuMnAs probed by optical and photoemission spectroscopy}},
volume = {97},
year = {2018}
}
  • [DOI] M. Asa, G. Vinai, J. L. Hart, C. Autieri, C. Rinaldi, P. Torelli, G. Panaccione, M. L. Taheri, S. Picozzi, and M. Cantoni, “Interdiffusion-driven synthesis of tetragonal chromium (III) oxide on BaTi O3,” Physical Review Materials, vol. 2, iss. 3, 2018.
    [Bibtex] 
    @article{Asa2018,
abstract = {{\textcopyright} 2018 American Physical Society. Interfaces play a crucial role in the study of novel phenomena emerging at heterostructures comprising metals and functional oxides. For this reason, attention should be paid to the interface chemistry, which can favor the interdiffusion of atomic species and, under certain conditions, lead to the formation of radically different compounds with respect to the original constituents. In this work, we consider Cr/BaTiO3 heterostructures grown on SrTiO3 (100) substrates. Chromium thin films (1-2 nm thickness) are deposited by molecular beam epitaxy on the BaTiO3 layer, and subsequently annealed in vacuum at temperatures ranging from 473 to 773 K. A disordered metallic layer is detected for annealing temperatures up to 573 K, whereas, at higher temperatures, we observe a progressive oxidation of chromium, which we relate to the thermally activated migration of oxygen from the substrate. The chromium oxidation state is +3 and the film shows a defective rocksalt structure, which grows lattice matched on the underlying BaTiO3 layer. One out of every three atoms of chromium is missing, producing an uncommon tetragonal phase with Cr2O3 stoichiometry. Despite the structural difference with respect to the ordinary corundum $\alpha$-Cr2O3 phase, we demonstrate both experimentally and theoretically that the electronic properties of the two phases are, to a large extent, equivalent.},
author = {Asa, M. and Vinai, G. and Hart, J.L. and Autieri, C. and Rinaldi, C. and Torelli, P. and Panaccione, G. and Taheri, M.L. and Picozzi, S. and Cantoni, M.},
doi = {10.1103/PhysRevMaterials.2.033401},
issn = {24759953},
journal = {Physical Review Materials},
number = {3},
title = {{Interdiffusion-driven synthesis of tetragonal chromium (III) oxide on BaTi O3}},
volume = {2},
year = {2018}
}
  • [DOI] I. M. Albo, S. Varotto, M. Asa, C. Rinaldi, M. Cantoni, R. Bertacco, and F. Morichetti, “Non-volatile switching of polycrystalline barium titanate films integrated in silicon photonic waveguides,” in Optics InfoBase Conference Papers, 2018.
    [Bibtex] 
    @inproceedings{Albo2018,
abstract = {{\textcopyright} 2018 The Author(s). Domain switching in polycrystalline BaTiO<inf>3</inf> is exploited to realize self-holding phase actuators in Si-photonics. A non-volatile change of the BaTiO<inf>3</inf> refractive-index is achieved and poly-BaTiO<inf>3</inf>-coated silicon photonic circuits are demonstrated.},
author = {Albo, I.M. and Varotto, S. and Asa, M. and Rinaldi, C. and Cantoni, M. and Bertacco, R. and Morichetti, F.},
booktitle = {Optics InfoBase Conference Papers},
doi = {10.1364/IPRSN.2018.ITu4I.2},
isbn = {9781557528209},
title = {{Non-volatile switching of polycrystalline barium titanate films integrated in silicon photonic waveguides}},
volume = {Part F101-},
year = {2018}
}
  • [DOI] I. Maqueira-Albo, S. Varotto, M. Asa, C. Rinaldi, M. Cantoni, R. Bertacco, and F. Morichetti, “Integration of Non-Volatile Ferroelectric Actuators in Silicon Photonics Circuits,” in International Conference on Transparent Optical Networks, 2018.
    [Bibtex] 
    @inproceedings{Maqueira-Albo2018,
abstract = {{\textcopyright} 2018 IEEE. In this work, we investigate a novel approach to realize non-volatile phase-actuators integrated in silicon photonic waveguides. We aim to exploit the ferroelectric response of polycrystalline BaTiO3 (poly-BTO) grown by pulsed laser deposition (PLD), whose domain can be re-oriented by applying an external electric field so as to induce a large change of the refractive index. Owing to the polarization remanence of ferroelectric materials, such refractive index variation is partially maintained when the electric field is turned off. Experimental results on poly-BTO demonstrate the possibility to achieve a non-volatile change of the poly-BTO refractive index in the order of 10-2, which is consistent with a 90° reorientation of the ferroelectric domains. We also integrated thin poly-BTO films in Si waveguides with a low additional propagation loss (<1 dB/mm), enabling the realization of photonic integrated circuits (PICs) with the proposed poly-BTO Si-photonics platform.},
author = {Maqueira-Albo, I. and Varotto, S. and Asa, M. and Rinaldi, C. and Cantoni, M. and Bertacco, R. and Morichetti, F.},
booktitle = {International Conference on Transparent Optical Networks},
doi = {10.1109/ICTON.2018.8473993},
isbn = {9781538666043},
issn = {21627339},
keywords = {ferroelectric,integrated optics materials,optical waveguides,photonic integrated circuits,silicon photonics},
title = {{Integration of Non-Volatile Ferroelectric Actuators in Silicon Photonics Circuits}},
volume = {2018-July},
year = {2018}
}
  • [DOI] C. Rinaldi, L. Baldrati, M. {Di Loreto}, M. Asa, R. Bertacco, and M. Cantoni, "Blocking Temperature Engineering in Exchange-Biased CoFeB/IrMn Bilayer," IEEE Transactions on Magnetics, vol. 54, iss. 4, 2018.
    [Bibtex] 
    @article{Rinaldi2018,
abstract = {{\textcopyright} 1965-2012 IEEE. In this paper, we report on the magnetic and chemical characterization of the exchange-biased CoFeB/IrMn bilayers, grown by magnetron sputtering on a Si-based platform and capped by either a Ru or MgO/Ru overlayer. For Ru capping, the blocking temperature monotonously increases with the IrMn thickness within the investigated range (3.5-8 nm). On the contrary, for MgO/Ru capping, the exchange bias is inhibited below 6 nm, whereas above 6 nm, the magnetic behavior is the same of Ru-capped films. The chemical analysis reveals a significant dependence of the Mn content from the capping layer for thin IrMn films (2.5 nm), whereas the difference disappears when IrMn becomes thick (7 nm). Our work suggests that a non-uniform composition of the IrMn films directly affects the exchange coupling at the IrMn/CoFeB interface.},
author = {Rinaldi, C. and Baldrati, L. and {Di Loreto}, M. and Asa, M. and Bertacco, R. and Cantoni, M.},
doi = {10.1109/TMAG.2017.2787623},
issn = {00189464},
journal = {IEEE Transactions on Magnetics},
keywords = {Antiferromagnetic (AFM) layer,exchange coupling,magnetic and spintronic materials,magnetic multilayers},
number = {4},
title = {{Blocking Temperature Engineering in Exchange-Biased CoFeB/IrMn Bilayer}},
volume = {54},
year = {2018}
}

2016

  • [DOI] L. Baldrati, C. Rinaldi, A. Manuzzi, M. Asa, L. Aballe, M. Foerster, N. Biškup, M. Varela, M. Cantoni, and R. Bertacco, "Artificial Multiferroics: Electrical Switching of Magnetization in the Artificial Multiferroic CoFeB/BaTiO3 (Adv. Electron. Mater. 7/2016)," Advanced Electronic Materials, vol. 2, iss. 7, 2016.
    [Bibtex] 
    @article{Baldrati2016,
author = {Baldrati, L and Rinaldi, C and Manuzzi, A and Asa, M and Aballe, L and Foerster, M and Bi{\v{s}}kup, N and Varela, M and Cantoni, M and Bertacco, R},
doi = {10.1002/aelm.201670041},
journal = {Advanced Electronic Materials},
number = {7},
title = {{Artificial Multiferroics: Electrical Switching of Magnetization in the Artificial Multiferroic CoFeB/BaTiO3 (Adv. Electron. Mater. 7/2016)}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978410146&doi=10.1002%2Faelm.201670041&partnerID=40&md5=8797de09c0277f84871be5bcc6c35612},
volume = {2},
year = {2016}
}
  • [DOI] M. Liebmann, C. Rinaldi, D. {Di Sante}, J. Kellner, C. Pauly, R. N. Wang, J. E. Boschker, A. Giussani, S. Bertoli, M. Cantoni, L. Baldrati, M. Asa, I. Vobornik, G. Panaccione, D. Marchenko, J. Sánchez-Barriga, O. Rader, R. Calarco, S. Picozzi, R. Bertacco, and M. Morgenstern, "Giant Rashba-Type Spin Splitting in Ferroelectric GeTe(111)," Advanced Materials, vol. 28, iss. 3, 2016.
    [Bibtex] 
    @article{Liebmann2016,
abstract = {{\textcopyright} 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Photoelectron spectroscopy in combination with piezoforce microscopy reveals that the helicity of Rashba bands is coupled to the nonvolatile ferroelectric polarization of GeTe(111). A novel surface Rashba band is found and fingerprints of a bulk Rashba band are identified by comparison with density functional theory calculations.},
author = {Liebmann, M. and Rinaldi, C. and {Di Sante}, D. and Kellner, J. and Pauly, C. and Wang, R.N. and Boschker, J.E. and Giussani, A. and Bertoli, S. and Cantoni, M. and Baldrati, L. and Asa, M. and Vobornik, I. and Panaccione, G. and Marchenko, D. and S{\'{a}}nchez-Barriga, J. and Rader, O. and Calarco, R. and Picozzi, S. and Bertacco, R. and Morgenstern, M.},
doi = {10.1002/adma.201503459},
issn = {15214095},
journal = {Advanced Materials},
keywords = {Rashba effect,ferroelectricity,photoelectron spectroscopy,piezoforce microscopy},
number = {3},
title = {{Giant Rashba-Type Spin Splitting in Ferroelectric GeTe(111)}},
volume = {28},
year = {2016}
}
  • [DOI] C. Rinaldi, J. C. Rojas-Sánchez, R. N. Wang, Y. Fu, S. Oyarzun, L. Vila, S. Bertoli, M. Asa, L. Baldrati, M. Cantoni, J. -M. George, R. Calarco, A. Fert, and R. Bertacco, "Evidence for spin to charge conversion in GeTe(111)," APL Materials, vol. 4, iss. 3, 2016.
    [Bibtex] 
    @article{Rinaldi2016,
abstract = {{\textcopyright} 2016 Author(s). GeTe has been predicted to be the father compound of a new class of multifunctional materials, ferroelectric Rashba semiconductors, displaying a coupling between spin-dependent k-splitting and ferroelectricity. In this paper, we report on epitaxial Fe/GeTe(111) heterostructures grown by molecular beam epitaxy. Spin-pumping experiments have been performed in a radio-frequency cavity by pumping a spin current from the Fe layer into GeTe at the Fe ferromagnetic resonance and detecting the transverse charge current originated in the slab due to spin-to-charge conversion. Preliminary experiments indicate that a clear spin to charge conversion exists, thus unveiling the potential of GeTe for spin-orbitronics.},
author = {Rinaldi, C. and Rojas-S{\'{a}}nchez, J.C. and Wang, R.N. and Fu, Y. and Oyarzun, S. and Vila, L. and Bertoli, S. and Asa, M. and Baldrati, L. and Cantoni, M. and George, J.-M. and Calarco, R. and Fert, A. and Bertacco, R.},
doi = {10.1063/1.4941276},
issn = {2166532X},
journal = {APL Materials},
number = {3},
title = {{Evidence for spin to charge conversion in GeTe(111)}},
volume = {4},
year = {2016}
}
  • [DOI] M. Monticelli, A. Torti, M. Cantoni, D. Petti, E. Albisetti, A. Manzin, E. Guerriero, R. Sordan, G. Gervasoni, M. Carminati, G. Ferrari, M. Sampietro, and R. Bertacco, "On-Chip Magnetic Platform for Single-Particle Manipulation with Integrated Electrical Feedback," Small, vol. 12, iss. 7, 2016.
    [Bibtex] 
    @article{Monticelli2016,
abstract = {{\textcopyright} 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Methods for the manipulation of single magnetic particles have become very interesting, in particular for in vitro biological studies. Most of these studies require an external microscope to provide the operator with feedback for controlling the particle motion, thus preventing the use of magnetic particles in high-throughput experiments. In this paper, a simple and compact system with integrated electrical feedback is presented, implementing in the very same device both the manipulation and detection of the transit of single particles. The proposed platform is based on zig-zag shaped magnetic nanostructures, where transverse magnetic domain walls are pinned at the corners and attract magnetic particles in suspension. By applying suitable external magnetic fields, the domain walls move to the nearest corner, thus causing the step by step displacement of the particles along the nanostructure. The very same structure is also employed for detecting the bead transit. Indeed, the presence of the magnetic particle in suspension over the domain wall affects the depinning field required for its displacement. This characteristic field can be monitored through anisotropic magnetoresistance measurements, thus implementing an integrated electrical feedback of the bead transit. In particular, the individual manipulation and detection of single 1-$\mu$m sized beads is demonstrated.},
author = {Monticelli, M. and Torti, A. and Cantoni, M. and Petti, D. and Albisetti, E. and Manzin, A. and Guerriero, E. and Sordan, R. and Gervasoni, G. and Carminati, M. and Ferrari, G. and Sampietro, M. and Bertacco, R.},
doi = {10.1002/smll.201500916},
issn = {16136829},
journal = {Small},
keywords = {anisotropic properties,lab-on-chip,magnetic beads,magnetic sensors,magnetic tweezers,magnetoresistance},
number = {7},
title = {{On-Chip Magnetic Platform for Single-Particle Manipulation with Integrated Electrical Feedback}},
volume = {12},
year = {2016}
}
  • [DOI] C. Rinaldi, S. Bertoli, M. Asa, L. Baldrati, C. Manzoni, M. Marangoni, G. Cerullo, M. Bianchi, R. Sordan, R. Bertacco, and M. Cantoni, "Determination of the spin diffusion length in germanium by spin optical orientation and electrical spin injection," Journal of Physics D: Applied Physics, vol. 49, iss. 42, 2016.
    [Bibtex] 
    @article{Rinaldi2016a,
abstract = {{\textcopyright} 2016 IOP Publishing Ltd. The measurement of the spin diffusion length and/or lifetime in semiconductors is a key issue for the realisation of spintronic devices, exploiting the spin degree of freedom of carriers for storing and manipulating information. In this paper, we address such parameters in germanium (0 0 1) at room temperature (RT) by three different measurement methods. Exploiting optical spin orientation in the semiconductor and spin filtering across an insulating MgO barrier, the dependence of the resistivity on the spin of photo-excited carriers in Fe/MgO/Ge spin photodiodes (spin-PDs) was electrically detected. A spin diffusion length of 0.9 0.2 $\mu$m was obtained by fitting the photon energy dependence of the spin signal by a mathematical model. Electrical techniques, comprising non-local four-terminal and Hanle measurements performed on CoFeB/MgO/Ge lateral devices, led to spin diffusion lengths of 1.3 0.2 $\mu$m and 1.3 0.08 $\mu$m, respectively. Despite minor differences due to experimental details, the order of magnitude of the spin diffusion length is the same for the three techniques. Although standard electrical methods are the most employed in semiconductor spintronics for spin diffusion length measurements, here we demonstrate optical spin orientation as a viable alternative for the determination of the spin diffusion length in semiconductors allowing for optical spin orientation.},
author = {Rinaldi, C. and Bertoli, S. and Asa, M. and Baldrati, L. and Manzoni, C. and Marangoni, M. and Cerullo, G. and Bianchi, M. and Sordan, R. and Bertacco, R. and Cantoni, M.},
doi = {10.1088/0022-3727/49/42/425104},
issn = {13616463},
journal = {Journal of Physics D: Applied Physics},
keywords = {germanium,optoelectronics,photodetector,polarimetry,spin diffusion},
number = {42},
title = {{Determination of the spin diffusion length in germanium by spin optical orientation and electrical spin injection}},
volume = {49},
year = {2016}
}
  • [DOI] L. Baldrati, C. Rinaldi, A. Manuzzi, M. Asa, L. Aballe, M. Foerster, N. Biškup, M. Varela, M. Cantoni, and R. Bertacco, "Electrical Switching of Magnetization in the Artificial Multiferroic CoFeB/BaTiO3," Advanced Electronic Materials, vol. 2, iss. 7, 2016.
    [Bibtex] 
    @article{Baldrati2016a,
abstract = {{\textcopyright} 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Electronic, magnetic, chemical, and mechanical phenomena occurring in metal/oxide heterostructures have recently received great attention in view of their exploitation in novel solid state devices. In particular, artificial multiferroics, i.e., layered or composite systems made of a ferromagnetic and ferroelectric phase, hold potential for achieving the electric control of the magnetization in spintronic devices. In this paper, a novel artificial multiferroic displaying perpendicular magnetic anisotropy is reported: the CoFeB/BaTiO3 bilayer. At room temperature, the CoFeB magnetic coercive field displays a hysteretic behavior, as a function of the voltage across the BaTiO3 layer, with a 60% variation for complete reversal of the ferroelectric BaTiO3 polarization. This is exploited to achieve the electric switching of the magnetization of individual CoFeB electrodes under a uniform magnetic bias field. Upon the local BaTiO3 polarization reversal, the CoFeB electrode jumps from an initial metastable state into the opposite stable magnetization state, with a characteristic switching time determined by magnetic viscosity. The magnetically assisted bipolar electric switching of the magnetization is demonstrated, via voltage pulses compatible with complementary metal-oxide semiconductor (CMOS) electronics, under uniform bias fields as low as 10 Oe.},
author = {Baldrati, L. and Rinaldi, C. and Manuzzi, A. and Asa, M. and Aballe, L. and Foerster, M. and Bi{\v{s}}kup, N. and Varela, M. and Cantoni, M. and Bertacco, R.},
doi = {10.1002/aelm.201600085},
issn = {2199160X},
journal = {Advanced Electronic Materials},
keywords = {artificial multiferroics,magnetic viscosity,magnetoelectric coupling,perpendicular magnetic anisotropy},
number = {7},
title = {{Electrical Switching of Magnetization in the Artificial Multiferroic CoFeB/BaTiO3}},
volume = {2},
year = {2016}
}
  • [DOI] L. Baldrati, C. Rinaldi, A. Manuzzi, M. Asa, L. Aballe, M. Foerster, N. Biškup, M. Varela, M. Cantoni, and R. Bertacco, "Artificial Multiferroics: Electrical Switching of Magnetization in the Artificial Multiferroic CoFeB/BaTiO3 (Adv. Electron. Mater. 7/2016)," Advanced Electronic Materials, vol. 2, iss. 7, 2016.
    [Bibtex] 
    @article{Baldrati2016b,
author = {Baldrati, L. and Rinaldi, C. and Manuzzi, A. and Asa, M. and Aballe, L. and Foerster, M. and Bi{\v{s}}kup, N. and Varela, M. and Cantoni, M. and Bertacco, R.},
doi = {10.1002/aelm.201670041},
issn = {2199160X},
journal = {Advanced Electronic Materials},
keywords = {artificial multiferroics,magnetic viscosity,magnetoelectric coupling,perpendicular magnetic anisotropy},
number = {7},
title = {{Artificial Multiferroics: Electrical Switching of Magnetization in the Artificial Multiferroic CoFeB/BaTiO3 (Adv. Electron. Mater. 7/2016)}},
volume = {2},
year = {2016}
}
  • [DOI] M. Cantoni and C. Rinaldi, "Light helicity detection in MOS-based spin-photodiodes: An analytical model," Journal of Applied Physics, vol. 120, iss. 10, 2016.
    [Bibtex] 
    @article{Cantoni2016,
abstract = {{\textcopyright} 2016 Author(s). In a metal-oxide-semiconductor-based spin-photodiode, the helicity of an incoming light is efficiently converted into an electrical signal by exploiting (i) the helicity dependence of the degree of optical spin orientation for photogenerated carriers in the semiconductor and (ii) the spin-dependent tunneling transmission of the insulating barrier between the semiconductor and a ferromagnetic metal. Here, we propose a theoretical model for predicting the electrical response of the device to a circularly polarized light, by integrating the Fert-Jaffr{\`{e}}s framework [A. Fert and H. Jaffr{\`{e}}s, Phys. Rev. B 64, 184420 (2001)] with a helicity-dependent photo-generation term. A figure of merit, related to the variation of the electrical response to the switching of the light helicity from right to left, is defined, and its dependence on the constitutive parameters of the device (barrier resistivity and spin selectivity, semiconductor resistivity and spin diffusion length) is shown. Finally, a simple analytical formula for identifying the optimal resistance barrier leading to the maximum efficiency is found and experimentally validated on Fe/MgO/Ge spin-photodiodes.},
author = {Cantoni, M. and Rinaldi, C.},
doi = {10.1063/1.4962204},
issn = {10897550},
journal = {Journal of Applied Physics},
number = {10},
title = {{Light helicity detection in MOS-based spin-photodiodes: An analytical model}},
volume = {120},
year = {2016}
}
  • [DOI] R. Bertacco and M. Cantoni, New trends in magnetic memories, , 2016.
    [Bibtex] 
    @book{Bertacco2016,
author = {Bertacco, R. and Cantoni, M.},
booktitle = {Ultra-High-Density Magnetic Recording: Storage Materials and Media Designs},
doi = {10.4032/9789814669597},
isbn = {9789814669597},
title = {{New trends in magnetic memories}},
year = {2016}
}

2015

  • [DOI] R. Bertacco, G. Radaelli, D. Petti, E. Plekhanov, I. Fina, M. Asa, L. Baldrati, C. Rinaldi, M. Cantoni, P. Torelli, D. Gutiérrez, G. Panaccione, M. Varela, S. Picozzi, and J. Fontcuberta, "Switching magnetic order at an Fe/BaTiO3 interface on and off: Impact on hybrid magnetic-ferroelectric tunnel junctions," in 2015 IEEE International Magnetics Conference, INTERMAG 2015, 2015.
    [Bibtex] 
    @inproceedings{Bertacco2015,
abstract = {{\textcopyright} 2015 IEEE. Interfacial magnetoelectric coupling for electrically altering the magnetization of ferromagnetic electrodes is a viable path to achieve the electrical writing of the magnetic information in spintronic devices. Exploiting the piezoelectric behavior of a ferroelectric material (FE) in contact with a ferromagnetic (FM) thin film, the electric control of the magnetic anisotropies can be achieved.[1] However, strain-mediated methods seems hardly suitable for integration in spintronic devices, where the piezoelectric activity of a FE layer would be inhibited by the growth on a substrate. This is the reason why there is a growing interest towards 'purely electric' magnetoelectric effects. For the paradigmatic Fe/BaTiO3 (BTO) system, sizable changes of the interfacial Fe magnetic moment upon reversal of the dielectric polarization of BTO have been predicted,[2] and sizable magneto-electric effects have been observed in nanometric hybrid magnetic-ferroelectric tunneling junctions.[3] Nevertheless, so far a clear understanding of the basic physical mechanisms leading to such a macroscopic effect is still lacking.},
author = {Bertacco, R. and Radaelli, G. and Petti, D. and Plekhanov, E. and Fina, I. and Asa, M. and Baldrati, L. and Rinaldi, C. and Cantoni, M. and Torelli, P. and Guti{\'{e}}rrez, D. and Panaccione, G. and Varela, M. and Picozzi, S. and Fontcuberta, J.},
booktitle = {2015 IEEE International Magnetics Conference, INTERMAG 2015},
doi = {10.1109/INTMAG.2015.7156521},
isbn = {9781479973224},
title = {{Switching magnetic order at an Fe/BaTiO3 interface on and off: Impact on hybrid magnetic-ferroelectric tunnel junctions}},
year = {2015}
}
  • [DOI] M. Asa, L. Baldrati, C. Rinaldi, S. Bertoli, G. Radaelli, M. Cantoni, and R. Bertacco, "Electric field control of magnetic properties and electron transport in BaTiO3-based multiferroic heterostructures," Journal of Physics Condensed Matter, vol. 27, iss. 50, 2015.
    [Bibtex] 
    @article{Asa2015,
abstract = {{\textcopyright} 2015 IOP Publishing Ltd. In this paper, we report on a purely electric mechanism for achieving the electric control of the interfacial spin polarization and magnetoresistance in multiferroic tunneling junctions. We investigate micrometric devices based on the Co/Fe/BaTiO3/La0.7Sr0.3MnO3 heterostructure, where Co/Fe and La0.7Sr0.3MnO3 are the magnetic electrodes and BaTiO3 acts both as a ferroelectric element and tunneling barrier. We show that, at 20 K, devices with a 2 nm thick BaTiO3 barrier present both tunneling electroresistance (TER = 12 ± 0.1%) and tunneling magnetoresistance (TMR). The latter depends on the direction of the BaTiO3 polarization, displaying a sizable change of the TMR from -0.32 ± 0.05% for the polarization pointing towards Fe, to -0.12 ± 0.05% for the opposite direction. This is consistent with the on-off switching of the Fe magnetization at the Fe/BaTiO3 interface, driven by the BaTiO3 polarization, we have previously demonstrated in x-ray magnetic circular dichroism experiments.},
author = {Asa, M. and Baldrati, L. and Rinaldi, C. and Bertoli, S. and Radaelli, G. and Cantoni, M. and Bertacco, R.},
doi = {10.1088/0953-8984/27/50/504004},
issn = {1361648X},
journal = {Journal of Physics Condensed Matter},
keywords = {BaTiO 3,antiferromagnetic,interface,magnetoelectric coupling,magnetotransport,multiferroic heterostructure,tunneling},
number = {50},
title = {{Electric field control of magnetic properties and electron transport in BaTiO3-based multiferroic heterostructures}},
volume = {27},
year = {2015}
}

2014

  • [DOI] G. Radaelli, D. Petti, E. Plekhanov, I. Fina, P. Torelli, B. R. Salles, M. Cantoni, C. Rinaldi, D. Gutiérrez, G. Panaccione, M. Varela, S. Picozzi, J. Fontcuberta, and R. Bertacco, "Electric control of magnetism at the Fe/BaTiO3interface," Nature Communications, vol. 5, 2014.
    [Bibtex] 
    @article{Radaelli2014,
author = {Radaelli, G and Petti, D and Plekhanov, E and Fina, I and Torelli, P and Salles, B R and Cantoni, M and Rinaldi, C and Guti{\'{e}}rrez, D and Panaccione, G and Varela, M and Picozzi, S and Fontcuberta, J and Bertacco, R},
doi = {10.1038/ncomms4404},
journal = {Nature Communications},
title = {{Electric control of magnetism at the Fe/BaTiO3interface}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84903893862&doi=10.1038%2Fncomms4404&partnerID=40&md5=32ac26c11c551e1bfdfe0ef6749b2466},
volume = {5},
year = {2014}
}
  • [DOI] F. Djeghloul, F. Ibrahim, M. Cantoni, M. Bowen, L. Joly, S. Boukari, P. Ohresser, F. Bertran, P. {Le Fèvre}, P. Thakur, F. Scheurer, T. Miyamachi, R. Mattana, P. Seneor, A. Jaafar, C. Rinaldi, S. Javaid, J. Arabski, J. -P. Kappler, W. Wulfhekel, N. B. Brookes, R. Bertacco, A. Taleb-Ibrahimi, M. Alouani, E. Beaurepaire, and W. Weber, "Direct observation of a highly spin-polarized organic spinterface at room temperature," in Proceedings of SPIE - The International Society for Optical Engineering, 2014.
    [Bibtex] 
    @inproceedings{Djeghloul2014,
abstract = {{\textcopyright} 2014 SPIE. Toward the design of large-scale electronic circuits that are entirely spintronics-driven, organic semiconductors have been identified as a promising medium to transport information using the electron spin. This requires a ferromagnetic metal-organic interface that is highly spin-polarized at and beyond room temperature, but this key building block is still lacking. We show how the interface between Co and phthalocyanine molecules constitutes a promising candidate. In fact, spin-polarized direct and inverse photoemission experiments reveal a high degree of spin polarization at room temperature at this interface.},
author = {Djeghloul, F. and Ibrahim, F. and Cantoni, M. and Bowen, M. and Joly, L. and Boukari, S. and Ohresser, P. and Bertran, F. and {Le F{\`{e}}vre}, P. and Thakur, P. and Scheurer, F. and Miyamachi, T. and Mattana, R. and Seneor, P. and Jaafar, A. and Rinaldi, C. and Javaid, S. and Arabski, J. and Kappler, J.-P. and Wulfhekel, W. and Brookes, N.B. and Bertacco, R. and Taleb-Ibrahimi, A. and Alouani, M. and Beaurepaire, E. and Weber, W.},
booktitle = {Proceedings of SPIE - The International Society for Optical Engineering},
doi = {10.1117/12.2060367},
isbn = {9781628411942},
issn = {1996756X},
keywords = {Organic spintronics,Spin-polarized interface states,Spin-polarized photoemission spectroscopy},
title = {{Direct observation of a highly spin-polarized organic spinterface at room temperature}},
volume = {9167},
year = {2014}
}
  • [DOI] M. Savoini, C. Piovera, C. Rinaldi, E. Albisetti, D. Petti, A. R. Khorsand, L. Duò, C. Dallera, M. Cantoni, R. Bertacco, M. Finazzi, E. Carpene, A. V. Kimel, A. Kirilyuk, and T. Rasing, "Bias-controlled ultrafast demagnetization in magnetic tunnel junctions," Physical Review B - Condensed Matter and Materials Physics, vol. 89, iss. 14, 2014.
    [Bibtex] 
    @article{Savoini2014,
abstract = {We report on the possibility of controlling the maximum demagnetization induced by a femtosecond laser pulse in a CoFeB-based magnetic tunnel junction, by tuning the external bias applied to the junction. We explain this effect in terms of laser-induced spin-polarized currents which can be controlled by tuning the conductivity of the junction. This demonstrates the contribution of spin-polarized currents for laser-induced demagnetization and may pave the way to increase the speed of spintronic devices, using ultrashort laser pulses. {\textcopyright} 2014 American Physical Society.},
author = {Savoini, M. and Piovera, C. and Rinaldi, C. and Albisetti, E. and Petti, D. and Khorsand, A.R. and Du{\`{o}}, L. and Dallera, C. and Cantoni, M. and Bertacco, R. and Finazzi, M. and Carpene, E. and Kimel, A.V. and Kirilyuk, A. and Rasing, T.},
doi = {10.1103/PhysRevB.89.140402},
issn = {1550235X},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {14},
title = {{Bias-controlled ultrafast demagnetization in magnetic tunnel junctions}},
volume = {89},
year = {2014}
}
  • [DOI] G. Radaelli, D. Petti, E. Plekhanov, I. Fina, P. Torelli, B. R. Salles, M. Cantoni, C. Rinaldi, D. Gutiérrez, G. Panaccione, M. Varela, S. Picozzi, J. Fontcuberta, and R. Bertacco, "Electric control of magnetism at the Fe/BaTiO3interface," Nature Communications, vol. 5, 2014.
    [Bibtex] 
    @article{Radaelli2014a,
abstract = {{\textcopyright} 2014 Macmillan Publishers Limited. Interfacial magnetoelectric coupling is a viable path to achieve electrical writing of magnetic information in spintronic devices. For the prototypical Fe/BaTiO3system, only tiny changes of the interfacial Fe magnetic moment upon reversal of the BaTiO3dielectric polarization have been predicted so far. Here, by using X-ray magnetic circular dichroism in combination with high-resolution electron microscopy and first principles calculations, we report on an undisclosed physical mechanism for interfacial magnetoelectric coupling in the Fe/BaTiO3system. At this interface, an ultrathin oxidized iron layer exists, whose magnetization can be electrically and reversibly switched on and off at room temperature by reversing the BaTiO3polarization. The suppression/recovery of interfacial ferromagnetism results from the asymmetric effect that ionic displacements in BaTiO3produces on the exchange coupling constants in the interfacial-oxidized Fe layer. The observed giant magnetoelectric response holds potential for optimizing interfacial magnetoelectric coupling in view of efficient, low-power spintronic devices.},
author = {Radaelli, G. and Petti, D. and Plekhanov, E. and Fina, I. and Torelli, P. and Salles, B.R. and Cantoni, M. and Rinaldi, C. and Guti{\'{e}}rrez, D. and Panaccione, G. and Varela, M. and Picozzi, S. and Fontcuberta, J. and Bertacco, R.},
doi = {10.1038/ncomms4404},
issn = {20411723},
journal = {Nature Communications},
title = {{Electric control of magnetism at the Fe/BaTiO3interface}},
volume = {5},
year = {2014}
}
  • [DOI] A. Brambilla, M. Cantoni, A. Picone, M. Riva, A. Calloni, G. Berti, G. Bussetti, P. Vavassori, M. Finazzi, L. Duò, and F. Ciccacci, "Magneto-optical investigation of Fe/CoO/Fe(001) trilayers," in Proceedings of SPIE - The International Society for Optical Engineering, 2014.
    [Bibtex] 
    @inproceedings{Brambilla2014,
abstract = {{\textcopyright} 2014 SPIE. In this paper, we report on the characterization of the magnetic properties of layered Fe/CoO/Fe(001) magnetic structures by means of Magneto-Optical Kerr Effect. Hysteresis loops were acquired on samples with variable CoO thickness, from 1 nm to 4 nm, and at different temperatures, from 30 K to room temperature. This characterization offers the opportunity of exploiting the differences in the layer-dependent sensitivity of Kerr rotation and Kerr ellipticity in order to disentangle the contribution of the different Fe layers in the hysteresis loops. Moreover, it allows us to give a detailed overview of the magnetic behavior of the trilayers.},
author = {Brambilla, A. and Cantoni, M. and Picone, A. and Riva, M. and Calloni, A. and Berti, G. and Bussetti, G. and Vavassori, P. and Finazzi, M. and Du{\`{o}}, L. and Ciccacci, F.},
booktitle = {Proceedings of SPIE - The International Society for Optical Engineering},
doi = {10.1117/12.2061691},
isbn = {9781628411942},
issn = {1996756X},
keywords = {Antiferromagnetic oxides,Exchange coupling,Layered magnetic structures,Magneto-optical kerr effect},
title = {{Magneto-optical investigation of Fe/CoO/Fe(001) trilayers}},
volume = {9167},
year = {2014}
}
  • [DOI] M. Carminati, G. Ferrari, S. U. Kwon, M. Sampietro, M. Monticelli, A. Torti, D. Petti, E. Albisetti, M. Cantoni, and R. Bertacco, "Towards the impedimetric tracking of single magnetically trailed microparticles," in 2014 IEEE 11th International Multi-Conference on Systems, Signals and Devices, SSD 2014, 2014.
    [Bibtex] 
    @inproceedings{Carminati2014,
abstract = {We present the design and the preliminary experimental characterization of a novel lab-on-a-chip platform for high-sensitivity impedimetric detection of single magnetic beads employed as magnetic cargos with molecular payload for accurate drug delivery. The real-time impedimetric detection of these superparamagnetic microbeads in saline solution is here experimentally demonstrated (20 nS conductance variation for a single 1$\mu$m bead), validating the insulating-sphere model and the finite-element simulations employed for optimal electrode design. A custom electronic front-end for impedance tracking in the 1-10 MHz range, required to compensate the impact of the large parasitic impedance due to the silicon substrate, is also presented. Thanks to introduction of an ad-hoc noise cancelling network based on a dummy circuit and a phase shifter for low-frequency phase noise counteraction by active subtraction, slow fluctuations are significantly reduced (by a factor 10), allowing a SNR > 10. {\textcopyright} 2014 IEEE.},
author = {Carminati, M. and Ferrari, G. and Kwon, S.U. and Sampietro, M. and Monticelli, M. and Torti, A. and Petti, D. and Albisetti, E. and Cantoni, M. and Bertacco, R.},
booktitle = {2014 IEEE 11th International Multi-Conference on Systems, Signals and Devices, SSD 2014},
doi = {10.1109/SSD.2014.6808828},
keywords = {Magnetic beads,drug delivery,impedance detection,microelectrodes},
title = {{Towards the impedimetric tracking of single magnetically trailed microparticles}},
year = {2014}
}
  • [DOI] M. Monticelli, D. Petti, E. Albisetti, M. Cantoni, E. Guerriero, R. Sordan, M. Carminati, G. Ferrari, M. Sampietro, and R. Bertacco, "Closed loop microfluidic platform based on domain wall magnetic conduits: A novel tool for biology and medicine," in Materials Research Society Symposium Proceedings, 2014.
    [Bibtex] 
    @inproceedings{Monticelli2014,
abstract = {Copyright {\textcopyright} Materials Research Society 2014{\^{A}}. In this paper we present an innovative on-chip platform suitable for the simultaneous manipulation and detection of the transit of a single magnetic bead. This system is based on the controlled displacement of constrained magnetic domain walls (DWs) that are used to move and sense particles in suspension over the chip. To this scope, the high stray field from the transverse DWs created at the corners of ferromagnetic zig-zag structures is used for particles manipulation, while electrical contacts flanking a single corner are employed to simultaneously monitor the DW passage through that corner, via anisotropic magneto resistance (AMR) measurements. A single DW carrying a magnetic particle is nucleated and manipulated within the zig-zag shaped magnetic conduit, trough the action of external magnetic fields. At the same time, the variation of the voltage drop across a corner flanked by a pair of electrical leads is measured, allowing to detect the transit of the DW thanks to the change of the relative orientation of current and spins at the corner related to the peculiar micromagnetic configuration of the DW (AMR). Work is in progress in order to selectively distinguish the transit of a naked DW from that of a DW bound to a magnetic particle. This work paves the way to the development of a closed-loop microlfuidic platform for on-chip bead manipulation, where single bead can be finely moved and their motion continuously checked, via AMR electrical detection and without need of optical monitoring, in a fully integrated closed-loop system.},
author = {Monticelli, M. and Petti, D. and Albisetti, E. and Cantoni, M. and Guerriero, E. and Sordan, R. and Carminati, M. and Ferrari, G. and Sampietro, M. and Bertacco, R.},
booktitle = {Materials Research Society Symposium Proceedings},
doi = {10.1557/opl.2014.925},
issn = {02729172},
keywords = {magnetoresistance (magnetic),magnetoresistance (transport),nanostructure},
title = {{Closed loop microfluidic platform based on domain wall magnetic conduits: A novel tool for biology and medicine}},
volume = {1686},
year = {2014}
}
  • [DOI] C. Rinaldi, S. Bertoli, M. Cantoni, C. Manzoni, M. Marangoni, G. Cerullo, M. Bianchi, R. Sordan, and R. Bertacco, "Determination of spin diffusion length in Germanium by optical and electrical spin injection," in Proceedings of SPIE - The International Society for Optical Engineering, 2014.
    [Bibtex] 
    @inproceedings{Rinaldi2014,
abstract = {{\textcopyright} 2014 SPIE. We report on the measurements of spin diffusion length and lifetime in Germanium with both magneto-electro-optical and magneto-electrical techniques. Magneto-electro-optical measurements were made by optically inject in Fe/MgO/Ge spin-photodiodes a spin polarized population around the T point of the Brillouin zone of Ge at different photon energies. The spin diffusion length is obtained by fitting by a mathematical model the photon energy dependence of the spin signal, due to switching of the light polarization from left to right, leading to a spin diffusion length of 0.9±0.2 $\mu$m at room temperature. Non-local four-terminals and Hanle measurements performed on Fe/MgO/Ge lateral devices, at room temperature, instead lead to 1.2±0.2 $\mu$m. The compatibility of these values among the different measurement methods validates the use all of all of them to determine the spin diffusion length in semiconductors. While electrical methods are well known in semiconductor spintronics, in this work we demonstrate that the optical pumping versus photon energy is an alternative and reliable method for the determination of the spin diffusion length whereas the band structure of the semiconductor allows for a non-negligible optical spin orientation.},
author = {Rinaldi, C. and Bertoli, S. and Cantoni, M. and Manzoni, C. and Marangoni, M. and Cerullo, G. and Bianchi, M. and Sordan, R. and Bertacco, R.},
booktitle = {Proceedings of SPIE - The International Society for Optical Engineering},
doi = {10.1117/12.2061591},
isbn = {9781628411942},
issn = {1996756X},
keywords = {Germanium,Hanle effect,Optical spin orientation,Spin diffusion length,Spin lifetime,Spin-optoelectronics,Spintronics},
title = {{Determination of spin diffusion length in Germanium by optical and electrical spin injection}},
volume = {9167},
year = {2014}
}
  • [DOI] C. Rinaldi, M. Cantoni, M. Marangoni, C. Manzoni, G. Cerullo, and R. Bertacco, "Wide-range optical spin orientation in Ge from near-infrared to visible light," Physical Review B - Condensed Matter and Materials Physics, vol. 90, iss. 16, 2014.
    [Bibtex] 
    @article{Rinaldi2014a,
abstract = {{\textcopyright} 2014 American Physical Society. Ge-based spin-photodiodes have been employed to investigate the spectral dependence of optical spin orientation in germanium, in the range 400-1550 nm. We found the expected maximum in the spin polarization of photocarriers for excitation at the direct gap in $\Gamma$ (1550 nm) and a second sizable peak due to photogeneration in the L valleys (530 nm). Data suggest distinct spin depolarization mechanisms for excitation at $\Gamma$ and L, with shorter spin relaxation times whether the X point is involved. These devices can be used as integrated photon-helicity detectors over a wide spectral range.},
author = {Rinaldi, C. and Cantoni, M. and Marangoni, M. and Manzoni, C. and Cerullo, G. and Bertacco, R.},
doi = {10.1103/PhysRevB.90.161304},
issn = {1550235X},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {16},
title = {{Wide-range optical spin orientation in Ge from near-infrared to visible light}},
volume = {90},
year = {2014}
}
  • [DOI] M. Cantoni, S. Boseggia, D. Petti, A. Cattoni, and R. Bertacco, "Structural comparison between MgO/Fe(0 0 1) and MgO/Fe(0 0 1)-p(1 × 1)O interfaces for magnetic tunneling junctions: An Auger electron diffraction study," Applied Surface Science, vol. 305, 2014.
    [Bibtex] 
    @article{Cantoni2014,
abstract = {Magnetic tunnel junctions based on MgO(0 0 1) barriers and ferromagnetic electrodes, such as Fe/MgO/Fe, represent a very popular and widely investigated subject in the field of spin-electronics because of the large values of magnetoresistance shown by these systems. In this paper, the structural properties of MgO thin films grown onto Fe(0 0 1) and MgO/Fe(0 0 1)-p(1 × 1)O surfaces, with MgO thickness ranging from 2 to 14 equivalent monolayers, have been investigated by means of Auger electron diffraction. The structural order and the crystal quality of the MgO films result practically independent from the template, the latter being either the clean Fe(0 0 1) surface or the oxidized Fe(0 0 1)-p(1 × 1)O one. This is confirmed by numerical simulations, showing that, apart from the first two MgO layers close to the interface, the structure is unaffected by the choice of the starting surface. By a structural point of view, we can conclude that Fe(0 0 1)-p(1 × 1)O is a good candidate for the role of bottom electrode for the realization of MgO-based magnetic tunnelling junctions, also considering its higher chemical stability and reproducibility if compared to the clean Fe(0 0 1) surface. {\textcopyright} 2014 Elsevier B.V.},
author = {Cantoni, M. and Boseggia, S. and Petti, D. and Cattoni, A. and Bertacco, R.},
doi = {10.1016/j.apsusc.2014.03.032},
issn = {01694332},
journal = {Applied Surface Science},
keywords = {Auger electron diffraction,Background subtraction,Fe(0 0 1)-p(1 × 1),Iron,Magnesium oxide,Magnetic tunneling junction},
title = {{Structural comparison between MgO/Fe(0 0 1) and MgO/Fe(0 0 1)-p(1 × 1)O interfaces for magnetic tunneling junctions: An Auger electron diffraction study}},
volume = {305},
year = {2014}
}
  • [DOI] G. Radaelli, M. Cantoni, L. Lijun, M. Espahbodi, and R. Bertacco, "Two dimensional growth of ultrathin Fe films on BaTiO3 with sharp chemical interface," Journal of Applied Physics, vol. 115, iss. 6, 2014.
    [Bibtex] 
    @article{Radaelli2014b,
abstract = {The Fe/BaTiO3 interface is a prototypical artificial multiferroic system displaying purely electronic magnetoelectric effects at room temperature. As magneto-electric coupling is essentially localized at the interface, the properties of the very first Fe layers in contact with BaTiO 3 play a major role. In this paper, we investigate, by using X-ray photoemission spectroscopy and photoelectron diffraction, the in-situ growth, by molecular beam epitaxy, of ultrathin Fe films (∼7 monolayers) on a BaTiO3/SrTiO3(001) template. We found that growing the Fe films above room temperature (373K) is essential in order to avoid island growth and obtain a continuous film. Post-annealing up to 473K improves the film crystallinity but prevents chemical interdiffusion and roughening. Just an interfacial monolayer of oxidized iron is detected in these conditions, which appears as an unavoidable consequence of the Fe/BaTiO3 chemical interaction. Its active role in magnetoelectric coupling must be carefully taken into account to correlate theoretical predictions and experiments. {\textcopyright} 2014 AIP Publishing LLC.},
author = {Radaelli, G. and Cantoni, M. and Lijun, L. and Espahbodi, M. and Bertacco, R.},
doi = {10.1063/1.4864375},
issn = {10897550},
journal = {Journal of Applied Physics},
number = {6},
title = {{Two dimensional growth of ultrathin Fe films on BaTiO3 with sharp chemical interface}},
volume = {115},
year = {2014}
}
  • [DOI] G. Radaelli, D. Petti, M. Cantoni, C. Rinaldi, and R. Bertacco, "Absence of strain-mediated magnetoelectric coupling at fully epitaxial Fe/BaTiO3 interface (invited)," Journal of Applied Physics, vol. 115, iss. 17, 2014.
    [Bibtex] 
    @article{Radaelli2014c,
abstract = {Interfacial MagnetoElectric coupling (MEC) at ferroelectric/ferromagnetic interfaces has recently emerged as a promising route to achieve electrical writing of magnetic information in spintronic devices. For the prototypical Fe/BaTiO3 (BTO) system, various MEC mechanisms have been theoretically predicted. Experimentally, it is well established that using BTO single crystal substrates MEC is dominated by strain-mediated mechanisms. In case of ferromagnetic layers epitaxially grown onto BTO films, instead, no direct evidence for MEC has been provided, apart from the results obtained on tunneling junction sandwiching a BTO tunneling barrier. In this paper, MEC at fully epitaxial Fe/BTO interface is investigated by Magneto-Optical Kerr Effect and magnetoresistance measurements on magnetic tunnel junctions fabricated on BTO. We find no evidence for strain-mediated MEC mechanisms in epitaxial systems, likely due to clamping of BTO to the substrate. Our results indicate that pure electronic MEC is the route of choice to be explored for achieving the electrical writing of information in epitaxial ferromagnet-ferroelectric heterostructures. {\textcopyright} 2014 AIP Publishing LLC.},
author = {Radaelli, G. and Petti, D. and Cantoni, M. and Rinaldi, C. and Bertacco, R.},
doi = {10.1063/1.4870915},
issn = {10897550},
journal = {Journal of Applied Physics},
number = {17},
title = {{Absence of strain-mediated magnetoelectric coupling at fully epitaxial Fe/BaTiO3 interface (invited)}},
volume = {115},
year = {2014}
}

2013

  • [DOI] F. Djeghloul, F. Ibrahim, M. Cantoni, M. Bowen, L. Joly, S. Boukari, P. Ohresser, F. Bertran, P. {Le Fèvre}, P. Thakur, F. Scheurer, T. Miyamachi, R. Mattana, P. Seneor, A. Jaafar, C. Rinaldi, S. Javaid, J. Arabski, J. -P. Kappler, W. Wulfhekel, N. B. Brookes, R. Bertacco, A. Taleb-Ibrahimi, M. Alouani, E. Beaurepaire, and W. Weber, "Direct observation of a highly spin-polarized organic spinterface at room temperature," Scientific Reports, vol. 3, 2013.
    [Bibtex] 
    @article{Djeghloul2013,
abstract = {Organic semiconductors constitute promising candidates toward large-scale electronic circuits that are entirely spintronics-driven. Toward this goal, tunneling magnetoresistance values above 300% at low temperature suggested the presence of highly spin-polarized device interfaces. However, such spinterfaces have not been observed directly, let alone at room temperature. Thanks to experiments and theory on the model spinterface between phthalocyanine molecules and a Co single crystal surface, we clearly evidence a highly efficient spinterface. Spin-polarised direct and inverse photoemission experiments reveal a high degree of spin polarisation at room temperature at this interface. We measured a magnetic moment on the molecule's nitrogen $\pi$ orbitals, which substantiates an ab-initio theoretical description of highly spin-polarised charge conduction across the interface due to differing spinterface formation mechanisms in each spin channel. We propose, through this example, a recipe to engineer simple organic-inorganic interfaces with remarkable spintronic properties that can endure well above room temperature.},
author = {Djeghloul, F. and Ibrahim, F. and Cantoni, M. and Bowen, M. and Joly, L. and Boukari, S. and Ohresser, P. and Bertran, F. and {Le F{\`{e}}vre}, P. and Thakur, P. and Scheurer, F. and Miyamachi, T. and Mattana, R. and Seneor, P. and Jaafar, A. and Rinaldi, C. and Javaid, S. and Arabski, J. and Kappler, J.-P. and Wulfhekel, W. and Brookes, N.B. and Bertacco, R. and Taleb-Ibrahimi, A. and Alouani, M. and Beaurepaire, E. and Weber, W.},
doi = {10.1038/srep01272},
issn = {20452322},
journal = {Scientific Reports},
title = {{Direct observation of a highly spin-polarized organic spinterface at room temperature}},
volume = {3},
year = {2013}
}
  • [DOI] E. Albisetti, D. Petti, M. Cantoni, F. Damin, A. Torti, M. Chiari, and R. Bertacco, "Conditions for efficient on-chip magnetic bead detection via magnetoresistive sensors," Biosensors and Bioelectronics, vol. 47, 2013.
    [Bibtex] 
    @article{Albisetti2013,
abstract = {A commonly used figure of merit of magnetoresistive sensors employed to detect magnetic beads labeling biomolecules in lab-on-chip applications is the sensor sensitivity (S0) to external magnetic fields in the linear region of the sensor. In this paper we show that, in case of lock-in detection and bead excitation by a small AC magnetic field, S0 is not the good figure of merit to optimize. Indeed, the highest sensitivity to the magnetic beads is achieved biasing the sensor in the region of its characteristics where the product between the DC bias field and the second derivative of the resistance with respect to the magnetic field is maximum. The validity of this criterion, derived from a phenomenological model of bead detection, is proved in case of magnetic tunneling junction sensors detecting magnetic beads with 250nm diameter. This work paves the way to the development of a new generation of sensors properly designed to maximize the bead sensitivity. {\textcopyright} 2013 Elsevier B.V.},
author = {Albisetti, E. and Petti, D. and Cantoni, M. and Damin, F. and Torti, A. and Chiari, M. and Bertacco, R.},
doi = {10.1016/j.bios.2013.03.016},
issn = {09565663},
journal = {Biosensors and Bioelectronics},
keywords = {Magnetic bead,Magnetic biosensor,Magnetic tunneling junction},
title = {{Conditions for efficient on-chip magnetic bead detection via magnetoresistive sensors}},
volume = {47},
year = {2013}
}

2012

  • [DOI] P. Torelli, M. Sperl, R. Ciancio, J. Fujii, C. Rinaldi, M. Cantoni, R. Bertacco, M. Utz, D. Bougeard, M. Soda, E. Carlino, G. Rossi, C. H. Back, and G. Panaccione, "Growth of ultrathin epitaxial Fe/MgO spin injector on (0, 0, 1) (Ga, Mn)As," Nanotechnology, vol. 23, iss. 46, 2012.
    [Bibtex] 
    @article{Torelli2012,
abstract = {We have grown an ultrathin epitaxial Fe/MgO bilayer on (Ga, Mn)As by e-beam evaporation in UHV. The system structure has been investigated by high resolution transmission electron microscopy (TEM) experiments which show that the Fe and MgO films, covering completely the (Ga, Mn)As, grow with the epitaxial relationship Fe[100](001)∥MgO[110](001)∥(Ga,Mn)As[110](001). The magnetic reversal process, studied by the magneto-optical Kerr effect (MOKE) at room temperature, demonstrates that the iron is ferromagnetic and possesses a cubic anisotropy, confirming the epitaxy relationship found with TEM. Resistivity measurements across the barrier display a non-Ohmic behavior characterized by cubic conductance as a function of the applied voltage suggesting tunneling-dominated transport across the barrier. {\textcopyright} 2012 IOP Publishing Ltd.},
author = {Torelli, P. and Sperl, M. and Ciancio, R. and Fujii, J. and Rinaldi, C. and Cantoni, M. and Bertacco, R. and Utz, M. and Bougeard, D. and Soda, M. and Carlino, E. and Rossi, G. and Back, C.H. and Panaccione, G.},
doi = {10.1088/0957-4484/23/46/465202},
issn = {09574484},
journal = {Nanotechnology},
number = {46},
title = {{Growth of ultrathin epitaxial Fe/MgO spin injector on (0, 0, 1) (Ga, Mn)As}},
volume = {23},
year = {2012}
}
  • [DOI] M. Cantoni, R. Bertacco, A. Brambilla, M. Finazzi, L. Duò, F. Ciccacci, A. Verdini, L. Floreano, A. Morgante, M. Passoni, C. S. Casari, and A. {Li Bassi}, "Fe nanoparticles on ZnSe: Reversible temperature dependence of the surface barrier potential," Physical Review B - Condensed Matter and Materials Physics, vol. 85, iss. 15, 2012.
    [Bibtex] 
    @article{Cantoni2012,
abstract = {The Fe growth on ZnSe(001) takes place via the initial formation of superparamagnetic nano-islands that subsequently coalesce, giving rise to a continuous film for a nominal thickness of 8 Fe monolayers. For a very low Fe coverage (2 Fe monolayers), we show that the surface barrier potential (i.e. the barrier potential seen by electrons incident on the surface), measured by absorbed current spectroscopy, attains very large values (6.9 eV at room temperature) and dramatically changes as a function of temperature, with an increase of ∼1.5 eV from room temperature down to 130 K, largely exceeding similar changes observed in both thin films and nanoparticles. This phenomenon disappears as the thickness increases and is fully reversible with temperature. Nonequilibrium phenomena due to the experimental conditions are present, but are not able to explain the observed data. Inverse photoemission, core level photoemission, x-ray photoemission diffraction, and scanning tunneling microscopy are employed in order to find temperature-dependent properties of the Fe islands: while only minor changes as a function of temperature are present in the electronic band structure, the Fe crystal structure, and the morphology of the islands, a noticeable temperature dependence of the Se segregation through the Fe islands is found. {\textcopyright} 2012 American Physical Society.},
author = {Cantoni, M. and Bertacco, R. and Brambilla, A. and Finazzi, M. and Du{\`{o}}, L. and Ciccacci, F. and Verdini, A. and Floreano, L. and Morgante, A. and Passoni, M. and Casari, C.S. and {Li Bassi}, A.},
doi = {10.1103/PhysRevB.85.155456},
issn = {10980121},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {15},
title = {{Fe nanoparticles on ZnSe: Reversible temperature dependence of the surface barrier potential}},
volume = {85},
year = {2012}
}
  • [DOI] C. Rinaldi, M. Cantoni, D. Petti, A. Sottocorno, M. Leone, N. M. Caffrey, S. Sanvito, and R. Bertacco, "Ge-based spin-photodiodes for room-temperature integrated detection of photon helicity," Advanced Materials, vol. 24, iss. 22, 2012.
    [Bibtex] 
    @article{Rinaldi2012,
abstract = {Spin-photodiodes based on Fe/MgO/Ge(001) heterostructures are reported. These devices perform the room-temperature integrated electrical detection of the spin polarization of a photocurrent generated by circularly polarized photons with a wavelength of 1300 nm, for light pulses with intensity I 0 down to 200 $\mu$W. A forward and reverse-biased average photocurrent variation of 5.9% is measured for the complete reversal of the incident light helicity. Copyright {\textcopyright} 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.},
author = {Rinaldi, C. and Cantoni, M. and Petti, D. and Sottocorno, A. and Leone, M. and Caffrey, N.M. and Sanvito, S. and Bertacco, R.},
doi = {10.1002/adma.201104256},
issn = {15214095},
journal = {Advanced Materials},
keywords = {magnetism,photonics,spin-optoelectronics,spintronics},
number = {22},
title = {{Ge-based spin-photodiodes for room-temperature integrated detection of photon helicity}},
volume = {24},
year = {2012}
}
  • [DOI] D. Petti, A. Stroppa, S. Picozzi, S. Brivio, M. Cantoni, and R. Bertacco, "Effect of Au proximity on the LSMO surface: An ab initio study," Journal of Magnetism and Magnetic Materials, vol. 324, iss. 17, 2012.
    [Bibtex] 
    @article{Petti2012,
abstract = {The effect of the proximity of Au on the electronic and magnetic properties of La 0.66Sr 0.33MnO 3 (LSMO) has been investigated by means of ab initio calculations within the density-functional theory. The calculations show an orbital reconstruction of the interfacial Mn, which is due more to the presence of a discontinuity rather than to a real chemical interaction with Au atoms. In fact, the same orbital reconstruction is found in the free LSMO surface. In both cases of Au/LSMO and LSMO surface, the Mn magnetic moments change very little with respect to the bulk case. In general, the calculations show a negligible influence of the Au atomic layer on LSMO at an ideal interface, with the LSMO surface magnetic and electronic properties essentially unchanged. {\textcopyright} 2012 Elsevier B.V.},
author = {Petti, D. and Stroppa, A. and Picozzi, S. and Brivio, S. and Cantoni, M. and Bertacco, R.},
doi = {10.1016/j.jmmm.2012.03.038},
issn = {03048853},
journal = {Journal of Magnetism and Magnetic Materials},
keywords = {DFT,Gold,Interface formation,LSMO,Magnetic property},
number = {17},
title = {{Effect of Au proximity on the LSMO surface: An ab initio study}},
volume = {324},
year = {2012}
}
  • [DOI] C. Rinaldi, M. Cantoni, D. Petti, and R. Bertacco, "Epitaxial Fe/MgO/Ge spin-photodiodes for integrated detection of light helicity at room temperature," Journal of Applied Physics, vol. 111, iss. 7, 2012.
    [Bibtex] 
    @article{Rinaldi2012a,
abstract = {We report on spin-photodiodes based on fully epitaxial Fe/MgO/Ge(001) heterostructures for the room temperature integrated detection of light helicity at a wavelength of 1300 nm. The degree of circular polarization of light is related to the spin direction of photo-excited carriers in Ge that are filtered by the MgO barrier, with probabilities differing for the two spin channels. Spin-detection experiments are performed by illuminating spin-photodiodes using left or right circularly polarized light under the application of a magnetic field parallel to the light direction and measuring the current crossing the device. We found that the maximum percentage variation of the photocurrent due to full reversal of the light helicity is on the order of 5.9 at room temperature. This variation can be attributed in part to the magnetic circular dichroism of Fe (0.8) but mainly to the spin filtering of photo-generated carriers across the MgO barrier. {\textcopyright} 2012 American Institute of Physics.},
author = {Rinaldi, C. and Cantoni, M. and Petti, D. and Bertacco, R.},
doi = {10.1063/1.3676243},
issn = {00218979},
journal = {Journal of Applied Physics},
number = {7},
title = {{Epitaxial Fe/MgO/Ge spin-photodiodes for integrated detection of light helicity at room temperature}},
volume = {111},
year = {2012}
}
  • [DOI] C. Rinaldi, M. Espahbodi, M. Cantoni, and R. Bertacco, "Spin-photodiodes for SiGe spin-optoelectronics," in Proceedings of SPIE - The International Society for Optical Engineering, 2012.
    [Bibtex] 
    @inproceedings{Rinaldi2012b,
abstract = {We report on spin-photodiodes based on fully epitaxial Fe/MgO/Ge(001) heterostructures for room temperature integrated detection of light helicity at 1300 nm and 1550 nm wavelengths. The degree of circular polarization of light determines the spin direction of photo-carriers in Ge that are filtered by the Fe/MgO analyzer. Spin-detection experiments are performed by measuring the photocurrent while illuminating the spin-photodiodes with left or right circularly polarized light, under the application of a magnetic field parallel to the light direction which drives the Fe magnetization out of plane. We found that the spin-photodiodes spin filtering asymmetry is reduced by ∼40% in forward bias and by less than 15% in reverse bias, when increasing the photon wavelength from 1300 nm to 1550 nm. This result, apparently counterintuitive because of the larger spin polarization of the photo-carriers generated at 1550 nm with respect to that at 1300 nm, is explained in terms of the different spatial profile of carrier generation inside Ge. The larger penetration depth of light at 1550 nm leads to a smaller polarization of photocarriers when they reach the MgO tunneling barrier, due to the more efficient spin relaxation during transport. {\textcopyright} 2012 SPIE.},
author = {Rinaldi, C. and Espahbodi, M. and Cantoni, M. and Bertacco, R.},
booktitle = {Proceedings of SPIE - The International Society for Optical Engineering},
doi = {10.1117/12.956474},
isbn = {9780819491787},
issn = {0277786X},
keywords = {Germanium,Polarimetry,Spin-Optoelectronics,Spin-photodiodes,Spintronics},
title = {{Spin-photodiodes for SiGe spin-optoelectronics}},
volume = {8461},
year = {2012}
}

2011

  • [DOI] M. Donolato, E. Sogne, B. T. Dalslet, M. Cantoni, D. Petti, J. Cao, F. Cardoso, S. Cardoso, P. P. Freitas, M. F. Hansen, and R. Bertacco, "On-chip measurement of the Brownian relaxation frequency of magnetic beads using magnetic tunneling junctions," Applied Physics Letters, vol. 98, iss. 7, 2011.
    [Bibtex] 
    @article{Donolato2011,
abstract = {We demonstrate the detection of the Brownian relaxation frequency of 250 nm diameter magnetic beads using a lab-on-chip platform based on current lines for exciting the beads with alternating magnetic fields and highly sensitive magnetic tunnel junction (MTJ) sensors with a superparamagnetic free layer. The first harmonic out-of-phase component of the MTJ response gives the imaginary part of the magnetic bead susceptibility, which peaks at the Brownian relaxation frequency. This work paves the way to on-chip implementation of Brownian magnetorelaxometry in innovative "lab-on-a-bead" assays for biomolecular recognition. {\textcopyright} 2011 American Institute of Physics.},
author = {Donolato, M. and Sogne, E. and Dalslet, B.T. and Cantoni, M. and Petti, D. and Cao, J. and Cardoso, F. and Cardoso, S. and Freitas, P.P. and Hansen, M.F. and Bertacco, R.},
doi = {10.1063/1.3554374},
issn = {00036951},
journal = {Applied Physics Letters},
number = {7},
title = {{On-chip measurement of the Brownian relaxation frequency of magnetic beads using magnetic tunneling junctions}},
volume = {98},
year = {2011}
}
  • [DOI] J. Gazquez, M. Varela, D. Petti, M. Cantoni, C. Rinaldi, S. Brivio, and R. Bertacco, "Aberration corrected scanning transmission electron microscopy and electron energy loss spectroscopy studies of epitaxial Fe/MgO/(001)Ge heterostructures," Journal of Materials Science, vol. 46, iss. 12, 2011.
    [Bibtex] 
    @article{Gazquez2011,
abstract = {Aberration correction in the scanning transmission electron microscope combined with electron energy loss spectroscopy allows simultaneous mapping of the structure, the chemistry and even the electronic properties of materials in one single experiment with spatial resolutions of the order of one {\AA}ngstr{\"{o}}m. Here the authors will apply these techniques to the characterization of epitaxial Fe/MgO/(001)Ge and interfaces with possible applications for tunneling junctions, and the authors will show that epitaxial MgO films can be grown on a (001)Ge substrates by molecular beam epitaxy and how it is possible to map the chemistry of interfaces with atomic resolution. {\textcopyright} 2011 Springer Science+Business Media, LLC (outside the USA).},
author = {Gazquez, J. and Varela, M. and Petti, D. and Cantoni, M. and Rinaldi, C. and Brivio, S. and Bertacco, R.},
doi = {10.1007/s10853-011-5248-7},
issn = {00222461},
journal = {Journal of Materials Science},
number = {12},
title = {{Aberration corrected scanning transmission electron microscopy and electron energy loss spectroscopy studies of epitaxial Fe/MgO/(001)Ge heterostructures}},
volume = {46},
year = {2011}
}
  • [DOI] D. Petti, M. Cantoni, C. Rinaldi, S. Brivio, R. Bertacco, J. Gazquez, and M. Varela, "Sharp Fe/MgO/Ge(001) epitaxial heterostructures for tunneling junctions," Journal of Applied Physics, vol. 109, iss. 8, 2011.
    [Bibtex] 
    @article{Petti2011,
abstract = {We report on the growth of epitaxial Fe/MgO/Ge(001) heterostructures by molecular beam epitaxy. The lowest oxidation and highest sharpness of the MgO/Ge interface, corresponding to a transition layer on the order of one Ge unit cell, is obtained for room temperature growth of the MgO layer followed by annealing in a vacuum at 500 °C. In these conditions, the MgO layer grows epitaxially on Ge(001) with the [110] direction parallel to the [100] direction of Ge, at variance with the cube-on-cube growth on Si(001) and GaAs(001). However, in some cases, the cube-on-cube growth mode of MgO on Ge competes with the mode involving a 45° rotation, as revealed by transmission electron microscopy and photoelectron diffraction data on MgO films grown at 300 °C without postannealing, and on p-doped Ge substrates. For the Fe overlayer, in all the cases reported, room temperature growth followed by annealing up to 200 °C gives rise to a sharp interface and the well-known 45° rotation of the Fe lattice with respect to the MgO lattice. {\textcopyright} 2011 American Institute of Physics.},
author = {Petti, D. and Cantoni, M. and Rinaldi, C. and Brivio, S. and Bertacco, R. and Gazquez, J. and Varela, M.},
doi = {10.1063/1.3554834},
issn = {00218979},
journal = {Journal of Applied Physics},
number = {8},
title = {{Sharp Fe/MgO/Ge(001) epitaxial heterostructures for tunneling junctions}},
volume = {109},
year = {2011}
}
  • [DOI] M. Cantoni, D. Petti, C. Rinaldi, and R. Bertacco, "Bandstructure line-up of epitaxial Fe/MgO/Ge heterostructures: A combined x-ray photoelectron spectroscopy and transport study," Applied Physics Letters, vol. 98, iss. 3, 2011.
    [Bibtex] 
    @article{Cantoni2011,
abstract = {The bandstructure line-up of Fe/MgO/Ge heterostructures with various Ge doping has been determined by x-ray photoemission spectroscopy. The MgO layer causes a sizable depinning of the Fermi level in Ge for light n- (10 15 cm-3) and moderate p -doping (1018 cm -3), but not for heavy n-doping (1020 cm-3). The Fermi level instead stays essentially in the middle of the MgO gap for all the investigated doping. This picture agrees with transport measurements only for moderate n- or p-doping, while we demonstrate that for heavy n-doping the analysis of the conductance versus temperature fails in predicting the Schottky barrier height. {\textcopyright} 2011 American Institute of Physics.},
author = {Cantoni, M. and Petti, D. and Rinaldi, C. and Bertacco, R.},
doi = {10.1063/1.3543851},
issn = {00036951},
journal = {Applied Physics Letters},
number = {3},
title = {{Bandstructure line-up of epitaxial Fe/MgO/Ge heterostructures: A combined x-ray photoelectron spectroscopy and transport study}},
volume = {98},
year = {2011}
}
  • [DOI] M. Cantoni, D. Petti, C. Rinaldi, and R. Bertacco, "Epitaxial growth of Fe/MgO/Ge(0 0 1) heterostructures," Microelectronic Engineering, vol. 88, iss. 4, 2011.
    [Bibtex] 
    @article{Cantoni2011a,
abstract = {We report on the growth of epitaxial Fe/MgO heterostructures on Ge(0 0 1) by Molecular Beam Epitaxy. The better crystal quality and interfacial chemical sharpness at the oxide-semiconductor interface have been obtained by growing MgO at room temperature, followed by a post-annealing at 773 K, on top of a p(2 × 1)-Ge(0 0 1) clean surface. The growth of Fe at room temperature followed by annealing at 473 K gives the best epitaxial structure with optimized crystallinity of each layer compatible with limited chemical interdiffusion. Tunneling devices based on the epitaxial Fe/MgO/Ge heterostructure have been micro-fabricated and tested in order to probe the electrical properties of the MgO barrier. The current-voltage characteristics clearly show that tunneling is the dominant phenomenon, thus indicating that this system is very promising for practical applications in electronics and spintronics. {\textcopyright} 2010 Elsevier B.V. All rights reserved.},
author = {Cantoni, M. and Petti, D. and Rinaldi, C. and Bertacco, R.},
doi = {10.1016/j.mee.2010.09.016},
issn = {01679317},
journal = {Microelectronic Engineering},
keywords = {Epitaxy,Germanium,MOS heterostructure,Magnesium oxide},
number = {4},
title = {{Epitaxial growth of Fe/MgO/Ge(0 0 1) heterostructures}},
volume = {88},
year = {2011}
}
  • [DOI] D. Petti, M. Cantoni, C. Rinaldi, and R. Bertacco, "Chemical and electronic properties of Fe/MgO/Ge heterostructures for spin electronics," in Journal of Physics: Conference Series, 2011.
    [Bibtex] 
    @inproceedings{Petti2011a,
abstract = {We report on the chemical and electronic properties of epitaxial Fe/MgO/Ge(001) heterostructures probed by X-ray Photoemission Spectroscopy. At variance with the Fe/MgO/Fe system, annealing at 570 K produces a sizable interdiffusion at the upper Fe/MgO interface, while at 470 K this process is inhibited. The XPS analysis of band alignment in heterostructures annealed at 470 K grown onto an intrinsic Ge substrate indicates that the Fermi level is placed at the center of the MgO gap and that the Schottky barrier height is 0.35±0.1 eV, thus indicating a partial depinning of the Fermi level.},
author = {Petti, D. and Cantoni, M. and Rinaldi, C. and Bertacco, R.},
booktitle = {Journal of Physics: Conference Series},
doi = {10.1088/1742-6596/292/1/012010},
issn = {17426596},
number = {1},
title = {{Chemical and electronic properties of Fe/MgO/Ge heterostructures for spin electronics}},
volume = {292},
year = {2011}
}

2010

  • [DOI] M. Cantoni, D. Petti, R. Bertacco, I. Pallecchi, D. Marŕ, G. Colizzi, A. Filippetti, and V. Fiorentini, "Band alignment at Cu2O/La0.7Sr0.3MnO 3 interface: A combined experimental-theoretical determination," Applied Physics Letters, vol. 97, iss. 3, 2010.
    [Bibtex] 
    @article{Cantoni2010,
author = {Cantoni, M and Petti, D and Bertacco, R and Pallecchi, I and Marŕ, D and Colizzi, G and Filippetti, A and Fiorentini, V},
doi = {10.1063/1.3467206},
journal = {Applied Physics Letters},
number = {3},
title = {{Band alignment at Cu2O/La0.7Sr0.3MnO 3 interface: A combined experimental-theoretical determination}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77956196867&doi=10.1063%2F1.3467206&partnerID=40&md5=f8880fcde6172335a2420946c64a9781},
volume = {97},
year = {2010}
}
  • [DOI] I. Pallecchi, L. Pellegrino, N. Banerjee, M. Cantoni, A. Gadaleta, A. S. Siri, and D. Marré, "Cu2O as a nonmagnetic semiconductor for spin transport in crystalline oxide electronics," Physical Review B - Condensed Matter and Materials Physics, vol. 81, iss. 16, 2010.
    [Bibtex] 
    @article{Pallecchi2010,
author = {Pallecchi, I and Pellegrino, L and Banerjee, N and Cantoni, M and Gadaleta, A and Siri, A S and Marr{\'{e}}, D},
doi = {10.1103/PhysRevB.81.165311},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {16},
title = {{Cu2O as a nonmagnetic semiconductor for spin transport in crystalline oxide electronics}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955372871&doi=10.1103%2FPhysRevB.81.165311&partnerID=40&md5=3c8b7e4375bb7b7de7e1e25de9b6d210},
volume = {81},
year = {2010}
}
  • [DOI] M. Donolato, P. Vavassori, M. Gobbi, M. Deryabina, M. F. Hansen, V. Metlushko, B. Ilic, M. Cantoni, D. Petti, S. Brivio, and R. Bertacco, "On-chip manipulation of protein-coated magnetic beads via domain-wall conduits," Advanced Materials, vol. 22, iss. 24, 2010.
    [Bibtex] 
    @article{Donolato2010,
abstract = {Geometrically constrained magnetic domain walls (DWs) in magnetic nanowires can be manipulated at the nanometer scale. The inhomogeneous magnetic stray field generated by a DW can capture a magnetic nanoparticle in solution. On-chip nanomanipulation of individual magnetic beads coated with proteins is demonstrated through the motion of geometrically constrained DWs in specially designed magnetic nanoconduits fully integrated in a lab-on-a-chip platform. Figure Presented {\textcopyright} 2010 WILEY-VCH Verlag GmbH & Co. KCaA, Weinheim.},
author = {Donolato, M. and Vavassori, P. and Gobbi, M. and Deryabina, M. and Hansen, M.F. and Metlushko, V. and Ilic, B. and Cantoni, M. and Petti, D. and Brivio, S. and Bertacco, R.},
doi = {10.1002/adma.201000146},
issn = {09359648},
journal = {Advanced Materials},
number = {24},
title = {{On-chip manipulation of protein-coated magnetic beads via domain-wall conduits}},
volume = {22},
year = {2010}
}
  • [DOI] S. Brivio, C. Magen, A. A. Sidorenko, D. Petti, M. Cantoni, M. Finazzi, F. Ciccacci, R. {De Renzi}, M. Varela, S. Picozzi, and R. Bertacco, "Effects of Au nanoparticles on the magnetic and transport properties of La0.67 Sr0.33 MnO3 ultrathin layers," Physical Review B - Condensed Matter and Materials Physics, vol. 81, iss. 9, 2010.
    [Bibtex] 
    @article{Brivio2010,
abstract = {The effect of the proximity of Au nanoparticles on the transport and magnetic properties of ultrathin La2/3 Sr1/3 MnO3 (LSMO) films has been investigated. We find a huge increase in the resistivity of the manganite (by four orders of magnitude for a Au nominal thickness of 2 nm), which is accompanied by a strong decrease in the Curie temperature. A combined scanning transmission electron microscopy and electron energy-loss spectroscopy analysis shows that interfaces are coherent and atomically sharp, and that the structural quality is very high. On the other hand, a strong reduction in the Mn oxidation state is seen upon Au capping. NMR data show a strong attenuation of the double exchange signal upon formation of Au nanoparticles. Ab initio calculations indicate a negligible influence of Au on LSMO at an ideal interface, with the LSMO surface magnetic and electronic properties essentially unchanged upon creation of the Au/LSMO interface. In view of these calculations, the experimental results cannot be explained in terms of purely electrostatic effects induced by the proximity of a noble metal. Here we propose that the main driving force underlying the observed change in physical properties is the high reactivity of Au nanoparticles, which can locally pump oxygen from the manganite, thus favoring a phase separation ensuing from O inhomogeneity which deteriorates the transport and electrical properties. {\textcopyright} 2010 The American Physical Society.},
author = {Brivio, S. and Magen, C. and Sidorenko, A.A. and Petti, D. and Cantoni, M. and Finazzi, M. and Ciccacci, F. and {De Renzi}, R. and Varela, M. and Picozzi, S. and Bertacco, R.},
doi = {10.1103/PhysRevB.81.094410},
issn = {10980121},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {9},
title = {{Effects of Au nanoparticles on the magnetic and transport properties of La0.67 Sr0.33 MnO3 ultrathin layers}},
volume = {81},
year = {2010}
}
  • [DOI] M. Donolato, M. Gobbi, P. Vavassori, M. Cantoni, V. Metlushko, B. Ilic, M. Zhang, S. X. Wang, M. F. Hansen, and R. Bertacco, "Detection of a single synthetic antiferromagnetic nanoparticle with an AMR nanostructure: Comparison between simulations and experiments," in Journal of Physics: Conference Series, 2010.
    [Bibtex] 
    @inproceedings{Donolato2010a,
abstract = {The depinning field of a domain wall in a permalloy nanostructure can be used to detect the presence of a magnetic particle. In this device the displacement of the domain wall in a sweeping magnetic field produces a variation of the voltage drop across a corner due to the anisotropic magnetoresistance effect and hence an electrical signal. In this paper we use micromagnetic simulations to calculate the output signal of a particularly shaped device in the presence of a single synthetic antiferromagnetic nanoparticle. The calculated magnetoresistive signal is in good agreement with corresponding experimental data {\textcopyright} 2010 IOP Publishing Ltd.},
author = {Donolato, M. and Gobbi, M. and Vavassori, P. and Cantoni, M. and Metlushko, V. and Ilic, B. and Zhang, M. and Wang, S.X. and Hansen, M.F. and Bertacco, R.},
booktitle = {Journal of Physics: Conference Series},
doi = {10.1088/1742-6596/200/12/122001},
issn = {17426596},
number = {SECTION 12},
title = {{Detection of a single synthetic antiferromagnetic nanoparticle with an AMR nanostructure: Comparison between simulations and experiments}},
volume = {200},
year = {2010}
}
  • [DOI] M. Cantoni, D. Petti, R. Bertacco, I. Pallecchi, D. Marŕ, G. Colizzi, A. Filippetti, and V. Fiorentini, "Band alignment at Cu2O/La0.7Sr0.3MnO 3 interface: A combined experimental-theoretical determination," Applied Physics Letters, vol. 97, iss. 3, 2010.
    [Bibtex] 
    @article{Cantoni2010a,
abstract = {Cu2O/La0.7Sr0.3MnO3 is a promising heterostructure for the realization of all-oxide spintronics devices, with La0.7Sr0.3MnO3 (LSMO) and Cu2 O playing the roles of ferromagnet and semiconductor, respectively. Here we use x-ray photoelectron spectroscopy and first principles calculations to determine the valence band offset at the Cu2O/LSMO interface. The interface band alignment is typical of a p-type semiconductor/metal contact, with an interface barrier of 0.3-0.5 eV depending on Cu2 O thickness. The calculated energetics indicates that the prevailing interface is between SrO-terminated LSMO and Cu planes of Cu2O. {\textcopyright} 2010 American Institute of Physics.},
author = {Cantoni, M. and Petti, D. and Bertacco, R. and Pallecchi, I. and Marŕ, D. and Colizzi, G. and Filippetti, A. and Fiorentini, V.},
doi = {10.1063/1.3467206},
issn = {00036951},
journal = {Applied Physics Letters},
number = {3},
title = {{Band alignment at Cu2O/La0.7Sr0.3MnO 3 interface: A combined experimental-theoretical determination}},
volume = {97},
year = {2010}
}
  • [DOI] P. Vavassori, M. Gobbi, M. Donolato, M. Cantoni, R. Bertacco, V. Metlushko, and B. Ilic, "Magnetic nanostructures for the manipulation of individual nanoscale particles in liquid environments (invited)," Journal of Applied Physics, vol. 107, iss. 9, 2010.
    [Bibtex] 
    @article{Vavassori2010,
abstract = {The manipulation of geometrically constrained magnetic domain walls (DWs) in nanoscale magnetic strips attracted much interest recently, with proposals for prospective memory and logic devices. Here we demonstrate that the high controllability of the motion of geometrically constrained DWs allows for the manipulation of individual nanoparticles in solution on a chip with the active control of position at the nanometer scale. Our approach exploits the fact that magnetic nanoparticles in suspension can be captured by a DW, whose position can be manipulated with nanometer scale accuracy in specifically designed magnetic nanowire structures. We hereby show that the precise control over DW nucleation, displacement, and annihilation processes in such nanostructures allows for the capture, transport, and release of magnetic nanoparticles. As magnetic nanoparticles with functionalized surfaces are widely used as molecule carriers or labels for single molecule studies, cell manipulation, and biomagnetic sensing, the accurate control over the handling of the single magnetic nanoparticle in suspension is a crucial building block for several applications in biotechnology, nanochemistry, and nanomedicine. {\textcopyright} 2010 American Institute of Physics.},
author = {Vavassori, P. and Gobbi, M. and Donolato, M. and Cantoni, M. and Bertacco, R. and Metlushko, V. and Ilic, B.},
doi = {10.1063/1.3352579},
issn = {00218979},
journal = {Journal of Applied Physics},
number = {9},
title = {{Magnetic nanostructures for the manipulation of individual nanoscale particles in liquid environments (invited)}},
volume = {107},
year = {2010}
}
  • [DOI] I. Pallecchi, L. Pellegrino, N. Banerjee, M. Cantoni, A. Gadaleta, A. S. Siri, and D. Marré, "Cu2O as a nonmagnetic semiconductor for spin transport in crystalline oxide electronics," Physical Review B - Condensed Matter and Materials Physics, vol. 81, iss. 16, 2010.
    [Bibtex] 
    @article{Pallecchi2010a,
abstract = {We probe spin transport in Cu2 O by measuring spin-valve effect in La0.7 Sr0.3 MnO3 / Cu2 O/Co and La0.7 Sr0.3 MnO3 / Cu2 O/ La 0.7 Sr0.3 MnO3 epitaxial heterostructures. In La0.7 Sr0.3 MnO3 / Cu2 O/Co systems, we find that a fraction of out-of-equilibrium spin-polarized carrier actually travel across the Cu2 O layer up to distances of almost 100 nm at low temperature. The corresponding spin-diffusion length dspin is estimated around 40 nm. Furthermore, we find that the insertion of a SrTiO 3 tunneling barrier does not improve spin injection, likely due to the matching of resistances at the interfaces. Our result on dspin may be likely improved, both in terms of Cu2 O crystalline quality and submicrometric morphology and in terms of device geometry, indicating that Cu2 O is a potential material for efficient spin transport in devices based on crystalline oxides. {\textcopyright} 2010 The American Physical Society.},
author = {Pallecchi, I. and Pellegrino, L. and Banerjee, N. and Cantoni, M. and Gadaleta, A. and Siri, A.S. and Marr{\'{e}}, D.},
doi = {10.1103/PhysRevB.81.165311},
issn = {10980121},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {16},
title = {{Cu2O as a nonmagnetic semiconductor for spin transport in crystalline oxide electronics}},
volume = {81},
year = {2010}
}
  • [DOI] D. Petti, M. Cantoni, M. Leone, R. Bertacco, and E. Rizzi, "Activation of Zr-Co-rare earth getter films: An XPS study," Applied Surface Science, vol. 256, iss. 21, 2010.
    [Bibtex] 
    @article{Petti2010,
abstract = {Thin films of non-evaporable getters are employed in the field of electronic devices packaging, as they provide a simple and effective solution for pumping in sealed applications. In particular thin films of Zr-Co-rare earth alloys deposited by sputtering have been developed for this purpose and successfully employed in industrial applications. In this paper we present an X-ray photoelectron spectroscopy investigation of the effect of thermal activation of the getter from the point of view of the induced surface chemical modification as seen by such a surface sensitive technique. We find that the activation process reflects in a clear reduction of Zr, accompanied by a decrease of the oxygen concentration at surface, which is fully accomplished already at 350 °C; while at 450 °C there is a significant increase of the cobalt concentration at surface. {\textcopyright} 2010 Elsevier B.V. All rights reserved.},
author = {Petti, D. and Cantoni, M. and Leone, M. and Bertacco, R. and Rizzi, E.},
doi = {10.1016/j.apsusc.2010.04.006},
issn = {01694332},
journal = {Applied Surface Science},
keywords = {Activation,Carbides,Non-evaporable getter,Oxidation,X-ray photoelectron spectroscopy,Zirconium},
number = {21},
title = {{Activation of Zr-Co-rare earth getter films: An XPS study}},
volume = {256},
year = {2010}
}
  • [DOI] C. Borioli, S. Franz, P. L. Cavallotti, M. Cantoni, and R. Bertacco, "Influence of magnetic fields on autocatalytic deposition of Co-Fe thin films," Journal of the Electrochemical Society, vol. 157, iss. 8, 2010.
    [Bibtex] 
    @article{Borioli2010,
abstract = {In the present paper, the effect of magnetic fields (17-98 mT) on the autocatalytic deposition of Co1-x-Fex (35-42 atom %) thin films is addressed. The deposition kinetics was strongly related to field intensity. Low magnetic fields (17 mT) increased the deposition rate by a factor of 2, whereas high magnetic fields (above 76 mT) completely inhibited the deposition process after a few minutes from the beginning of the reaction. Alloy composition was also affected by the application of magnetic fields. Depending on the intensity of the applied field, the Fe content in the alloy gradually changed from 36 to 41 atom % below 200 nm and from 42 to 37 atom % above 200 nm of thickness. On average, the application of magnetic fields during the deposition process increased the coercivity of thin Co-Fe films and made them anisotropic, with the extent of such an effect depending on film thickness. {\textcopyright} 2010 The Electrochemical Society.},
author = {Borioli, C. and Franz, S. and Cavallotti, P.L. and Cantoni, M. and Bertacco, R.},
doi = {10.1149/1.3432585},
issn = {00134651},
journal = {Journal of the Electrochemical Society},
number = {8},
title = {{Influence of magnetic fields on autocatalytic deposition of Co-Fe thin films}},
volume = {157},
year = {2010}
}
  • [DOI] S. Brivio, M. Cantoni, D. Petti, and R. Bertacco, "Near-room-temperature control of magnetization in field effect devices based on La0.67 Sr0.33 MnO3 thin films," Journal of Applied Physics, vol. 108, iss. 11, 2010.
    [Bibtex] 
    @article{Brivio2010a,
abstract = {The control of the magnetization in ferromagnetic layers via electric fields is a hot topic in view of applications to the next generation of spintronic devices, where writing the magnetic information through current lines could be replaced by electric writing. Mixed valence manganites are good candidates for such a purpose because they present an intriguing coupling between ferromagnetism and charge ordering/doping which can be tuned by the application of an electric field. Here we present results on the near-room temperature control of the magnetization of optimally doped La0.67 Sr0.33 MnO3 ultrathin films in vertical field effect devices, where they act as top or bottom electrodes. In the latter case a slight decrease in the Curie temperature (∼5 K) is observed after application of 5× 107 V/m, i.e., the maximum field preventing electric breakdown, compatible with the induced variation in the charge density and mixed valence within the Thomas Fermi screening length. These results indicate that electric fields achievable in vertical field effect devices, of the same entity of interfacial fields originating from differences in the work function in heterostructures, have only minor influence on the magnetic properties of optimally doped ultrathin La0.67 Sr0.33 MnO3 films. {\textcopyright} 2010 American Institute of Physics.},
author = {Brivio, S. and Cantoni, M. and Petti, D. and Bertacco, R.},
doi = {10.1063/1.3516283},
issn = {00218979},
journal = {Journal of Applied Physics},
number = {11},
title = {{Near-room-temperature control of magnetization in field effect devices based on La0.67 Sr0.33 MnO3 thin films}},
volume = {108},
year = {2010}
}

2009

  • [DOI] M. Donolato, M. Gobbi, P. Vavassori, M. Leone, M. Cantoni, V. Metlushko, B. Ilic, M. Zhang, S. X. Wang, and R. Bertacco, "Nanosized corners for trapping and detecting magnetic nanoparticles," Nanotechnology, vol. 20, iss. 38, 2009.
    [Bibtex] 
    @article{Donolato2009,
abstract = {We present a device concept based on controlled micromagnetic configurations in a corner-shaped permalloy nanostructure terminated with two circular disks, specifically designed for the capture and detection of a small number of magnetic beads in suspension. A transverse head-to-head domain wall (TDW) placed at the corner of the structure plays the role of an attracting pole for magnetic beads. The TDW is annihilated in the terminating disks by applying an appropriate magnetic field, whose value is affected by the presence of beads chemically bound to the surface. In the case where the beads are not chemically bound to the surface, the annihilation of the TDW causes their release into the suspension. The variation of the voltage drop across the corner, due to the anisotropic magnetoresistance (AMR) while sweeping the magnetic field, is used to detect the presence of a chemically bound bead. The device response has been characterized by using both synthetic antiferromagnetic nanoparticles (disks of 70nm diameter and 20nm height) and magnetic nanobeads, for different thicknesses of the protective capping layer. We demonstrate the detection down to a single nanoparticle, therefore the device holds the potential for the localization and detection of small numbers of molecules immobilized on the particle's functionalized surface. {\textcopyright} 2009 IOP Publishing Ltd.},
author = {Donolato, M. and Gobbi, M. and Vavassori, P. and Leone, M. and Cantoni, M. and Metlushko, V. and Ilic, B. and Zhang, M. and Wang, S.X. and Bertacco, R.},
doi = {10.1088/0957-4484/20/38/385501},
issn = {09574484},
journal = {Nanotechnology},
number = {38},
title = {{Nanosized corners for trapping and detecting magnetic nanoparticles}},
volume = {20},
year = {2009}
}
  • [DOI] P. Vavassori, M. Gobbi, M. Donolato, V. Metlushko, B. Ilic, M. Cantoni, D. Petti, S. Brivio, and R. Bertacco, "Manipulation at the nano-scale of single magnetic particles via domain walls conduits," in Proceedings of the 2009 International Conference on Electromagnetics in Advanced Applications, ICEAA '09, 2009.
    [Bibtex] 
    @inproceedings{Vavassori2009,
abstract = {We demonstrate on-chip manipulation of individual nanoparticles in suspension with active control of position at the nanometer scale, through the control of the motion of geometrically constrained domain walls (DWs) in magnetic nano-conduits. Magnetic nanoparticles are captured by the stray field of a DW and their transport and release is obtained via precise control over DW nucleation, displacement, and annihilation processes. In comparison with other manipulation techniques, our approach is unique because it combines the true single nano-particle manipulation ability at the nanoscale and the compatibility with lab-on-chip applications. As magnetic nano-particles are widely used for tagging molecules or cells, our method holds great potential for biological applications involving manipulation, transport and sorting of molecules and cells on surfaces. This work opens the way towards the realization of microchip-based platforms for high-throughput cell manipulation or single molecule analysis and synthesis. {\textcopyright} 2009 IEEE.},
author = {Vavassori, P. and Gobbi, M. and Donolato, M. and Metlushko, V. and Ilic, B. and Cantoni, M. and Petti, D. and Brivio, S. and Bertacco, R.},
booktitle = {Proceedings of the 2009 International Conference on Electromagnetics in Advanced Applications, ICEAA '09},
doi = {10.1109/ICEAA.2009.5297344},
isbn = {9781424433865},
title = {{Manipulation at the nano-scale of single magnetic particles via domain walls conduits}},
year = {2009}
}
  • [DOI] A. Brambilla, P. Sessi, M. Cantoni, M. Finazzi, N. Rougemaille, R. Belkhou, P. Vavassori, L. Duò, and F. Ciccacci, "Frustration-driven micromagnetic structure in Fe/CoO/Fe thin film layered systems," Physical Review B - Condensed Matter and Materials Physics, vol. 79, iss. 17, 2009.
    [Bibtex] 
    @article{Brambilla2009,
abstract = {We have investigated the micromagnetic structure of magnetic domains in Fe/CoO/Fe trilayer systems and the magnetization coupling between the iron layers. We observe very small magnetic domains separated by nanometer-sized domain walls in the top Fe layer for a narrow CoO thickness range. Such domains have lateral dimensions as low as 30 nm and present topologies which are very similar to those observed in the top layer of Fe/NiO/Fe trilayers. Both magnetic domain structure and Fe interlayer coupling dramatically change with the CoO thickness. The role of magnetocrystalline anisotropy and magnetic frustrations on the observed phenomenology is discussed. {\textcopyright} 2009 The American Physical Society.},
author = {Brambilla, A. and Sessi, P. and Cantoni, M. and Finazzi, M. and Rougemaille, N. and Belkhou, R. and Vavassori, P. and Du{\`{o}}, L. and Ciccacci, F.},
doi = {10.1103/PhysRevB.79.172401},
issn = {10980121},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {17},
title = {{Frustration-driven micromagnetic structure in Fe/CoO/Fe thin film layered systems}},
volume = {79},
year = {2009}
}
  • R. Bertacco, M. Donolato, M. Gobbi, M. Cantoni, D. Petti, S. Brivio, V. Metlushko, B. Ilic, and P. Vavassori, "On-chip manipulation of single magnetic nano-particles via domain walls conduits," in 2009 9th IEEE Conference on Nanotechnology, IEEE NANO 2009, 2009.
    [Bibtex] 
    @inproceedings{Bertacco2009,
abstract = {We demonstrate on-chip manipulation of individual nanoparticles in suspension with active control of position at the nanometer scale, through the control of the motion of geometrically constrained domain walls (DWs) in magnetic nano-conduits. Magnetic nanoparticles are captured by the stray field of a DW and their transport and release is obtained via precise control over DW nucleation, displacement, and annihilation processes. In comparison with other manipulation techniques, our approach is unique because it combines the true single nano-particle manipulation ability at the nanoscale and the compatibility with lab-on-chip applications. As magnetic nano-particles are widely used for tagging molecules or cells, our method holds great potential for biological applications involving manipulation, transport and sorting of molecules and cells on surfaces. This work opens the way towards the realization of microchip-based platforms for high-throughput cell manipulation or single molecule analysis and synthesis. {\textcopyright} 2009 IEEE NANO Organizers.},
author = {Bertacco, R. and Donolato, M. and Gobbi, M. and Cantoni, M. and Petti, D. and Brivio, S. and Metlushko, V. and Ilic, B. and Vavassori, P.},
booktitle = {2009 9th IEEE Conference on Nanotechnology, IEEE NANO 2009},
isbn = {9789810836948},
title = {{On-chip manipulation of single magnetic nano-particles via domain walls conduits}},
year = {2009}
}
  • [DOI] A. Cattoni, D. Petti, S. Brivio, M. Cantoni, R. Bertacco, and F. Ciccacci, "MgO/Fe(001) and MgO/Fe (001) -p (1×1) O interfaces for magnetic tunnel junctions: A comparative study," Physical Review B - Condensed Matter and Materials Physics, vol. 80, iss. 10, 2009.
    [Bibtex] 
    @article{Cattoni2009,
abstract = {The chemical, structural, and electronic properties of MgO/Fe(001) and MgO/Fe (001) -p (1×1) O interfaces for magnetic tunnel junctions (MTJs) have been widely investigated by means of electron spectroscopy. In particular, we present a detailed analysis of the spin-resolved electronic structure above the Fermi level, carried out by spin-polarized inverse photoemission and absorbed current spectroscopy. The MgO barrier presents good crystallinity and sharp interfaces when grown both onto Fe(001) and Fe (001) -p (1×1) O. Moreover, we find that the exchange splitting of unoccupied bands is essentially the same for the two MgO/Fe interfaces, even though it is different for the two starting surfaces, being larger in Fe (001) -p (1×1) O than in Fe(001). Our findings indicate that Fe (001) -p (1×1) O is a good candidate for the realization of heterostructures for magnetic tunnel junctions because of its high chemical stability and reproducibility, as compared to clean Fe(001). {\textcopyright} 2009 The American Physical Society.},
author = {Cattoni, A. and Petti, D. and Brivio, S. and Cantoni, M. and Bertacco, R. and Ciccacci, F.},
doi = {10.1103/PhysRevB.80.104437},
issn = {10980121},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {10},
title = {{MgO/Fe(001) and MgO/Fe (001) -p (1×1) O interfaces for magnetic tunnel junctions: A comparative study}},
volume = {80},
year = {2009}
}
  • [DOI] M. Cantoni, R. Bertacco, A. Brambilla, and F. Ciccacci, "Photon- and electron-induced surface voltage in electron spectroscopies on ZnSe(0 0 1)," Journal of Electron Spectroscopy and Related Phenomena, vol. 173, iss. 2-3, 2009.
    [Bibtex] 
    @article{Cantoni2009,
abstract = {The surface band bending in ZnSe(0 0 1), as a function of the temperature, is investigated both in the valence band (by photoemission) and in the conduction band (by inverse photoemission and absorbed current spectroscopies). Two different mechanisms are invoked for interpreting the experimental data: the band bending due to surface states, and the surface voltage induced by the incident beam. While the latter is well known in photoemission (surface photovoltage), we demonstrate the existence of a similar effect in inverse photoemission and absorbed current spectroscopies, induced by the incident electrons instead of photons. These results point to the importance of considering the surface voltage effect even in electron-in techniques for a correct evaluation of the band bending. {\textcopyright} 2009 Elsevier B.V. All rights reserved.},
author = {Cantoni, M. and Bertacco, R. and Brambilla, A. and Ciccacci, F.},
doi = {10.1016/j.elspec.2009.05.005},
issn = {03682048},
journal = {Journal of Electron Spectroscopy and Related Phenomena},
keywords = {Absorbed current,Inverse photoemission,Photoemission,Surface band bending,Surface photovoltage,ZnSe},
number = {2-3},
title = {{Photon- and electron-induced surface voltage in electron spectroscopies on ZnSe(0 0 1)}},
volume = {173},
year = {2009}
}

2008

  • [DOI] C. Magen, M. Varela, S. J. Pennycook, S. Brivio, D. Petti, M. Cantoni, and R. Bertacco, "Influence of Au electrodes on the properties of SrTiO3/La 0.67Sr0.33MnO3/Au magnetic tunnel junctions studied by aberration-corrected STEM-EELS," Microscopy and Microanalysis, vol. 14, iss. SUPPL. 2, p. 1392–1393, 2008.
    [Bibtex] 
    @article{Magen20081392,
author = {Magen, C and Varela, M and Pennycook, S J and Brivio, S and Petti, D and Cantoni, M and Bertacco, R},
doi = {10.1017/S1431927608086212},
journal = {Microscopy and Microanalysis},
number = {SUPPL. 2},
pages = {1392--1393},
title = {{Influence of Au electrodes on the properties of SrTiO3/La 0.67Sr0.33MnO3/Au magnetic tunnel junctions studied by aberration-corrected STEM-EELS}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-49549114648&doi=10.1017%2FS1431927608086212&partnerID=40&md5=acad955ed0a0e6626739059bf21d8b6d},
volume = {14},
year = {2008}
}
  • [DOI] R. Bertacco, A. Tagliaferri, M. Riva, L. Signorini, M. Cantoni, A. Cattoni, F. Ciccacci, B. A. Davidson, F. Maccherozzi, I. Vobornik, and G. Panaccione, "Surface electronic and magnetic properties of La2/3 Sr1/3 MnO3 thin films with extended metallicity above the Curie temperature," Physical Review B - Condensed Matter and Materials Physics, vol. 78, iss. 3, 2008.
    [Bibtex] 
    @article{Bertacco2008,
abstract = {The surface electronic and magnetic properties of epitaxial La2/3 Sr1/3 MnO3 / SrTiO3 (001) films with extended bulk metallicity above the Curie temperature have been investigated. By angle-resolved photoemission we show that the surface electronic structure presents the eg dispersing band, responsible for the half-metallicity, crossing the Fermi level and leading to a sharp Fermi edge. Quasiparticle excitations, reflecting the coherent polaronic ferromagnetic and metallic ground state, are clearly visible at the Fermi level and 16 K, while they disappear at room temperature, where a Fermi edge is still clearly visible. X-ray magnetic circular dichroism shows a robust subsurface magnetization up to TC, while spin-polarization Mott spectroscopy indicates a rapid suppression of the surface magnetization which disappears around room temperature. These results clearly demonstrate that a robust surface metallic electronic structure does not necessarily ensure the concomitant stabilization of long-range magnetic order. {\textcopyright} 2008 The American Physical Society.},
author = {Bertacco, R. and Tagliaferri, A. and Riva, M. and Signorini, L. and Cantoni, M. and Cattoni, A. and Ciccacci, F. and Davidson, B.A. and Maccherozzi, F. and Vobornik, I. and Panaccione, G.},
doi = {10.1103/PhysRevB.78.035448},
issn = {10980121},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {3},
title = {{Surface electronic and magnetic properties of La2/3 Sr1/3 MnO3 thin films with extended metallicity above the Curie temperature}},
volume = {78},
year = {2008}
}
  • [DOI] C. Magen, M. Varela, S. J. Pennycook, S. Brivio, D. Petti, M. Cantoni, and R. Bertacco, "Influence of Au electrodes on the properties of SrTiO3/La 0.67Sr0.33MnO3/Au magnetic tunnel junctions studied by aberration-corrected STEM-EELS," Microscopy and Microanalysis, vol. 14, iss. SUPPL. 2, 2008.
    [Bibtex] 
    @article{Magen2008,
author = {Magen, C. and Varela, M. and Pennycook, S.J. and Brivio, S. and Petti, D. and Cantoni, M. and Bertacco, R.},
doi = {10.1017/S1431927608086212},
issn = {14319276},
journal = {Microscopy and Microanalysis},
number = {SUPPL. 2},
title = {{Influence of Au electrodes on the properties of SrTiO3/La 0.67Sr0.33MnO3/Au magnetic tunnel junctions studied by aberration-corrected STEM-EELS}},
volume = {14},
year = {2008}
}
  • [DOI] P. Vavassori, V. Metlushko, B. Ilic, M. Gobbi, M. Donolato, M. Cantoni, and R. Bertacco, "Domain wall displacement in Py square ring for single nanometric magnetic bead detection," Applied Physics Letters, vol. 93, iss. 20, 2008.
    [Bibtex] 
    @article{Vavassori2008,
abstract = {An approach based on domain wall displacement in confined ferromagnetic nanostructures for attracting and sensing a single nanometric magnetic particle is presented. We modeled and experimentally demonstrated the viability of the approach using an anisotropic magnetoresistance device made by a micron-sized square ring of Permalloy. This detection concept can be suitable to biomolecular recognition and, in particular, to single molecule detection. {\textcopyright} 2008 American Institute of Physics.},
author = {Vavassori, P. and Metlushko, V. and Ilic, B. and Gobbi, M. and Donolato, M. and Cantoni, M. and Bertacco, R.},
doi = {10.1063/1.3030984},
issn = {00036951},
journal = {Applied Physics Letters},
number = {20},
title = {{Domain wall displacement in Py square ring for single nanometric magnetic bead detection}},
volume = {93},
year = {2008}
}
  • [DOI] A. Cattoni, R. Bertacco, M. Cantoni, F. Ciccacci, H. {Von Kaenel}, and G. J. Norga, "Impact of O 2 exposure on surface crystallinity of clean and Ba terminated Ge(1 0 0) surfaces," Applied Surface Science, vol. 254, iss. 9, 2008.
    [Bibtex] 
    @article{Cattoni2008,
abstract = {In analogy with the case of Sr on Si [Y. Liang, S. Gan, M. Engelhard, Appl. Phys. Lett. 79 (2001) 3591], we studied surface crystallinity and oxidation behaviour of clean and Ba terminated Ge(1 0 0) surfaces as a function of oxygen pressure and temperature. The structural and chemical changes in the Ge surface layer were monitored by LEED, XPS and real-time RHEED. In contrast to the oxidation retarding effect, observed for 1/2 monolayer of Sr on Si, the presence of a Ba termination layer leads to a pronounced increase in Ge oxidation rate with respect to clean Ge. In fact, while the Ge(1 0 0) surface terminated with 1/2 ML Ba amorphizes for a pO 2 of 10 -2 Torr, LEED indicates that clean Ge forms a thin (4.5 {\AA}), 1 × 1 ordered oxide upon aggressive O 2 exposure (150 Torr, 200 °C, 30 min). We briefly discuss the origins for the difference in behaviour between Ba on Ge and Sr on Si. {\textcopyright} 2007 Elsevier B.V. All rights reserved.},
author = {Cattoni, A. and Bertacco, R. and Cantoni, M. and Ciccacci, F. and {Von Kaenel}, H. and Norga, G.J.},
doi = {10.1016/j.apsusc.2007.10.018},
issn = {01694332},
journal = {Applied Surface Science},
keywords = {Ba,Ge,Oxide epitaxy,RHEED,Surface passivation,Surface termination,XPS},
number = {9},
title = {{Impact of O 2 exposure on surface crystallinity of clean and Ba terminated Ge(1 0 0) surfaces}},
volume = {254},
year = {2008}
}
  • [DOI] D. Petti, R. Bertacco, S. Brivio, M. Cantoni, A. Cattoni, and F. Ciccacci, "X-ray photoemission study of the Au La0.67 Sr0.33 Mn O3 interface formation," Journal of Applied Physics, vol. 103, iss. 4, 2008.
    [Bibtex] 
    @article{Petti2008,
abstract = {We report an x-ray photoemission spectroscopy study of the Au La0.67 Sr0.33 Mn O3 interface formation, aiming to investigate interface abruptness and possible chemical interdiffusion. Our results indicate that the gold deposition does not affect the chemical properties of manganite film and no interdiffusion or segregation takes place. {\textcopyright} 2008 American Institute of Physics.},
author = {Petti, D. and Bertacco, R. and Brivio, S. and Cantoni, M. and Cattoni, A. and Ciccacci, F.},
doi = {10.1063/1.2844459},
issn = {00218979},
journal = {Journal of Applied Physics},
number = {4},
title = {{X-ray photoemission study of the Au La0.67 Sr0.33 Mn O3 interface formation}},
volume = {103},
year = {2008}
}
  • [DOI] A. Brambilla, P. Sessi, M. Cantoni, L. Duò, M. Finazzi, and F. Ciccacci, "Epitaxial growth and characterization of CoO/Fe(001) thin film layered structures," Thin Solid Films, vol. 516, iss. 21, 2008.
    [Bibtex] 
    @article{Brambilla2008,
abstract = {By means of X-ray photoemission spectroscopy and low energy electron diffraction, we show that it is possible to grow good quality thin epitaxial CoO films on Fe(001) substrates, through deposition in oxygen atmosphere. In particular, the composition and the structure of CoO(001)/Fe(001) bilayer systems and Fe(001)/CoO(001)/Fe(001) trilayer systems have been investigated by monitoring the evolution of the chemical interactions at the interfaces as a function of CoO thickness and growth temperature. We observe the presence of Fe oxides at the CoO/Fe interface and of a thin layer of metallic cobalt at the upper Fe/CoO interface of trilayer systems. {\textcopyright} 2008 Elsevier B.V. All rights reserved.},
author = {Brambilla, A. and Sessi, P. and Cantoni, M. and Du{\`{o}}, L. and Finazzi, M. and Ciccacci, F.},
doi = {10.1016/j.tsf.2008.04.058},
issn = {00406090},
journal = {Thin Solid Films},
keywords = {Cobalt oxide,Iron,Molecular beam epitaxy,X-ray photoemission spectroscopy},
number = {21},
title = {{Epitaxial growth and characterization of CoO/Fe(001) thin film layered structures}},
volume = {516},
year = {2008}
}

2007

  • [DOI] M. Cantoni, R. Bertacco, F. Ciccacci, E. Puppin, E. Pinotti, M. Brenna, M. Marangolo, M. Eddrieff, P. Torelli, F. Maccherozzi, J. Fujii, and G. Panaccione, "Temperature-dependent magnetism of Fe thin films on ZnSe(0 0 1)," Journal of Magnetism and Magnetic Materials, vol. 316, iss. 2 SPEC. ISS., 2007.
    [Bibtex] 
    @article{Cantoni2007,
abstract = {We present X-ray magnetic circular dichroism (XMCD) and magneto-optical Kerr effect (MOKE) data on the magnetic properties of Fe/ZnSe(0 0 1) thin films at increasing Fe coverage. The magnetic behaviour of the Fe overlayer is superparamagnetic for a coverage up to 6 monolayers whereas, above this threshold, a truly ferromagnetic phase shows up. XMCD and MOKE data show that this behaviour is substantially unchanged in the temperature range 10-300 K for all the investigated coverages: these findings imply that the blocking temperature is definitely below 10 K. {\textcopyright} 2007 Elsevier B.V. All rights reserved.},
author = {Cantoni, M. and Bertacco, R. and Ciccacci, F. and Puppin, E. and Pinotti, E. and Brenna, M. and Marangolo, M. and Eddrieff, M. and Torelli, P. and Maccherozzi, F. and Fujii, J. and Panaccione, G.},
doi = {10.1016/j.jmmm.2007.03.014},
issn = {03048853},
journal = {Journal of Magnetism and Magnetic Materials},
keywords = {Blocking temperature,Coercivity,Superparamagnetism,Thin film,ZnSe},
number = {2 SPEC. ISS.},
title = {{Temperature-dependent magnetism of Fe thin films on ZnSe(0 0 1)}},
volume = {316},
year = {2007}
}
  • [DOI] R. Bertacco, S. Brivio, M. Cantoni, A. Cattoni, D. Petti, M. Finazzi, F. Ciccacci, A. A. Sidorenko, M. Ghidini, G. Allodi, and R. {De Renzi}, "Proximity effects induced by a gold layer on La0.67 Sr0.33 Mn O3 thin films," Applied Physics Letters, vol. 91, iss. 10, 2007.
    [Bibtex] 
    @article{Bertacco2007,
abstract = {The authors report about La0.67 Sr0.33 Mn O3 single crystal manganite thin films in interaction with a gold capping layer. With respect to uncoated manganite layers of the same thickness, Au-capped 4 nm thick manganite films reveal a dramatic reduction (≃185 K) of the Curie temperature TC and a lower saturation low temperature magnetization M0. A sizable TC reduction (≃60 K) is observed even when an inert SrTi O3 layer is inserted between the gold film and the 4 nm thick manganite layer, suggesting that this effect might have an electrostatic origin. {\textcopyright} 2007 American Institute of Physics.},
author = {Bertacco, R. and Brivio, S. and Cantoni, M. and Cattoni, A. and Petti, D. and Finazzi, M. and Ciccacci, F. and Sidorenko, A.A. and Ghidini, M. and Allodi, G. and {De Renzi}, R.},
doi = {10.1063/1.2778353},
issn = {00036951},
journal = {Applied Physics Letters},
number = {10},
title = {{Proximity effects induced by a gold layer on La0.67 Sr0.33 Mn O3 thin films}},
volume = {91},
year = {2007}
}
  • [DOI] S. Brivio, M. Cantoni, D. Petti, A. Cattoni, R. Bertacco, M. Finazzi, F. Ciccacci, A. Sidorenko, G. Allodi, M. Ghidini, and R. de Renzi, "Decrease of the Curie temperature in La0.67Sr0.33MnO3 thin films induced by Au capping," Materials Science and Engineering B: Solid-State Materials for Advanced Technology, vol. 144, iss. 1-3, 2007.
    [Bibtex] 
    @article{Brivio2007,
abstract = {Ferromagnetism of La0.67Sr0.33MnO3 is extremely sensitive to external perturbations like substrate-induced strain, charge injection and chemical interactions with neighbour layers. In this paper we discuss the perturbation induced by the presence of a metallic overlayer, typically deposited for electric contacts, in the prototypical case of the Au/La0.67Sr0.33MnO3 interface. In particular we found a sizable decrease of the Curie temperature in thin films of La0.67Sr0.33MnO3 after gold capping: 65 K for 5 nm thickness of the manganite. Apart from chemical reactions at the interface, charge injection-depletion induced by the difference in the work function between Au and La0.67Sr0.33MnO3 could partially explain this phenomenon. {\textcopyright} 2007 Elsevier B.V. All rights reserved.},
author = {Brivio, S. and Cantoni, M. and Petti, D. and Cattoni, A. and Bertacco, R. and Finazzi, M. and Ciccacci, F. and Sidorenko, A. and Allodi, G. and Ghidini, M. and de Renzi, R.},
doi = {10.1016/j.mseb.2007.07.084},
issn = {09215107},
journal = {Materials Science and Engineering B: Solid-State Materials for Advanced Technology},
keywords = {Curie temperature,Gold,Manganites,PLD},
number = {1-3},
title = {{Decrease of the Curie temperature in La0.67Sr0.33MnO3 thin films induced by Au capping}},
volume = {144},
year = {2007}
}
  • [DOI] S. Picozzi, C. Ma, Z. Yang, R. Bertacco, M. Cantoni, A. Cattoni, D. Petti, S. Brivio, and F. Ciccacci, "Oxygen vacancies and induced changes in the electronic and magnetic structures of La0.66 Sr0.33 Mn O3: A combined ab initio and photoemission study," Physical Review B - Condensed Matter and Materials Physics, vol. 75, iss. 9, 2007.
    [Bibtex] 
    @article{Picozzi2007,
abstract = {The effect of oxygen vacancies on the electronic and magnetic properties of La0.66 Sr0.33 Mn O3 (LSMO) has been investigated by means of ab initio calculations within the density-functional formalism combined with photoemission. The simulations show that the introduction of oxygen vacancies causes a shift of the valence-band features toward higher binding energies and an increase of the degree of covalency of Mn bondings. The Mn magnetic moments undergo some changes, keeping, however, the situation relatively close to the ideal nondefective system: in none of the different vacancy configurations, a drastic charge or spin rearrangement occurs. There is, though, an important vacancy-induced drawback: half-metallicity, typical of the perfectly stoichiometric system, is generally lost due to defective bands that cross the Fermi level. Photoemission experiments performed on epitaxial thin films of LSMO with different contents of oxygen vacancies grown by pulsed laser deposition essentially confirm theoretical predictions. Our findings clearly indicate that the control over oxygen deficiency should therefore be experimentally achieved to avoid unwanted consequences in terms of spin-injection efficiency. {\textcopyright} 2007 The American Physical Society.},
author = {Picozzi, S. and Ma, C. and Yang, Z. and Bertacco, R. and Cantoni, M. and Cattoni, A. and Petti, D. and Brivio, S. and Ciccacci, F.},
doi = {10.1103/PhysRevB.75.094418},
issn = {10980121},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {9},
title = {{Oxygen vacancies and induced changes in the electronic and magnetic structures of La0.66 Sr0.33 Mn O3: A combined ab initio and photoemission study}},
volume = {75},
year = {2007}
}
  • [DOI] C. Borioli, S. Franz, M. Bestetti, M. Cantoni, and P. L. Cavallotti, "Magnetic properties of Co-Fe ultra-thin films by electroless deposition," in ECS Transactions, 2007.
    [Bibtex] 
    @inproceedings{Borioli2007,
abstract = {The deposition kmetics and the magnetic properties of Co x-Fe1-x (30

2006

  • [DOI] C. Borioli, S. Franz, M. Bestetti, M. Cantoni, and P. L. Cavallotti, "Magnetic properties of Co-Fe ultra-thin films by electroless deposition," in ECS Transactions, 2006, p. 81–90.
    [Bibtex] 
    @conference{Borioli200681,
author = {Borioli, C and Franz, S and Bestetti, M and Cantoni, M and Cavallotti, P L},
booktitle = {ECS Transactions},
doi = {10.1149/1.2753241},
number = {25},
pages = {81--90},
title = {{Magnetic properties of Co-Fe ultra-thin films by electroless deposition}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-45249111163&doi=10.1149%2F1.2753241&partnerID=40&md5=8d581e6189f6294df769533612e425f0},
volume = {3},
year = {2006}
}
  • [DOI] A. Cattoni, R. Bertacco, M. Riva, M. Cantoni, F. Ciccacci, H. {Von Känel}, and G. J. Norga, "Effect of Ba termination layer on chemical and electrical passivation of Ge (1 0 0) surfaces," Materials Science in Semiconductor Processing, vol. 9, iss. 4-5 SPEC. ISS., 2006.
    [Bibtex] 
    @article{Cattoni2006,
abstract = {During the deposition process of high-k gate oxides on Ge, the Ge interface tends to be oxidized to form GeOx, leading to the introduction of interface states which compromise transistor performance. It has been suggested that a Ba termination layer on Ge could fulfill the same passivating role on Ge as reported for Sr on Si. In this paper, we present LEED, UPS and XPS studies on the effect of Ba overlayers on the chemical and electrical passivation of Ge(1 0 0). For 1 ML coverage, the adsorbate phase has (1×1) symmetry, as observed by LEED. Ba is seen to significantly increase the oxidation tendency of the Ge(1 0 0) surface. Using UPS, 1 ML Ba was seen to reduce surface band bending by 200 meV on n-type Ge, suggesting that Ba deposition causes transfer of electrons to the Ge substrate, resulting in a surface dipole. The role of this dipole in oxidation enhancement and possible electronic passivation effects is discussed. {\textcopyright} 2006 Elsevier Ltd. All rights reserved.},
author = {Cattoni, A. and Bertacco, R. and Riva, M. and Cantoni, M. and Ciccacci, F. and {Von K{\"{a}}nel}, H. and Norga, G.J.},
doi = {10.1016/j.mssp.2006.08.075},
issn = {13698001},
journal = {Materials Science in Semiconductor Processing},
keywords = {Chemical and electrical passivation,Oxidation},
number = {4-5 SPEC. ISS.},
title = {{Effect of Ba termination layer on chemical and electrical passivation of Ge (1 0 0) surfaces}},
volume = {9},
year = {2006}
}
  • [DOI] M. Cantoni, M. Riva, G. Isella, R. Bertacco, and F. Ciccacci, "Ultrathin Fe films on single crystal and virtual Ge(0 0 1) substrates: Towards the control of magnetic properties," Applied Surface Science, vol. 252, iss. 15, 2006.
    [Bibtex] 
    @article{Cantoni2006,
abstract = {Ultrathin Fe films have been epitaxially grown at room temperature on standard single crystal Ge(0 0 1) substrates and virtual Ge/Si(0 0 1) substrates. Their magnetic and electronic properties have been investigated in situ by spin polarized inverse photoemission and magneto-optical Kerr effect. In both cases, the onset of ferromagnetism appears definitively at 3 ML, and the overall behavior is very similar in the case of standard and virtual substrates, so that the latter can be employed for growing high quality Fe/Ge/Si interfaces. All the films investigated display uniaxial anisotropy, which is explained in terms of the surface morphology induced by the preparation conditions. {\textcopyright} 2005 Elsevier B.V. All rights reserved.},
author = {Cantoni, M. and Riva, M. and Isella, G. and Bertacco, R. and Ciccacci, F.},
doi = {10.1016/j.apsusc.2005.12.052},
issn = {01694332},
journal = {Applied Surface Science},
keywords = {Magnetic anisotropy,Nanostructures,Spin polarized inverse photoemission,Spintronics,Virtual substrate},
number = {15},
title = {{Ultrathin Fe films on single crystal and virtual Ge(0 0 1) substrates: Towards the control of magnetic properties}},
volume = {252},
year = {2006}
}
  • [DOI] L. Signorini, M. Riva, M. Cantoni, R. Bertacco, and F. Ciccacci, "Epitaxial La2 / 3Sr1 / 3MnO3 thin films with unconventional magnetic and electric properties near the Curie temperature," Thin Solid Films, vol. 515, iss. 2 SPEC. ISS., 2006.
    [Bibtex] 
    @article{Signorini2006,
abstract = {We used Pulsed Laser Deposition (PLD) in oxidizing environment to epitaxially grow optimally doped manganite La2 / 3Sr1 / 3MnO3 (LSMO) thin films over a (001) oriented SrTiO3 substrate. Synthesized samples show good room temperature magnetic properties accompanied by a peculiar extension of the metallic conduction regime to temperatures higher than the Curie point. In this paper we present a study of the dependence of transport and magnetic properties of LSMO thin films on the oxygen pressure during PLD growth. We show how interaction of the growing films with O2 molecules is fundamental for a correct synthesis and in which way it is possible to adjust PLD experimental parameters in order to tune LSMO thin film properties. The persistence of the metallic conduction regime above the Curie temperature indicates some minor changes of the electronic structure near the Fermi level, which is responsible for the half-metallic behavior of LSMO at low temperature. This feature is rather intriguing from the technological point of view, as it could pave the way to the increase of operating temperature of devices based on LSMO. {\textcopyright} 2006 Elsevier B.V. All rights reserved.},
author = {Signorini, L. and Riva, M. and Cantoni, M. and Bertacco, R. and Ciccacci, F.},
doi = {10.1016/j.tsf.2005.12.277},
issn = {00406090},
journal = {Thin Solid Films},
keywords = {Magnetic thin films,Manganites,Pulsed laser deposition},
number = {2 SPEC. ISS.},
title = {{Epitaxial La2 / 3Sr1 / 3MnO3 thin films with unconventional magnetic and electric properties near the Curie temperature}},
volume = {515},
year = {2006}
}
  • [DOI] M. Cantoni, M. Riva, R. Bertacco, and F. Ciccacci, "Uniaxial magnetic anisotropies in Fe films on single crystal and virtual Ge(001) substrates studied with spin polarized inverse photoemission and MOKE," Physical Review B - Condensed Matter and Materials Physics, vol. 74, iss. 13, 2006.
    [Bibtex] 
    @article{Cantoni2006a,
abstract = {Fe films have been grown at room temperature on standard Ge(001) single crystals and virtual Ge Si1-x Gex Si (001) substrates, and their magnetic properties extensively investigated in situ by spin polarized inverse photoemission and magneto-optical Kerr effect. Two different uniaxial anisotropies have been found to coexist. The first one, giving rise to a [110] easy axis, is associated to the Fe Ge interface: it disappears at large thickness (more than 10 Fe layers), while dominates in very thin films (5 Fe layers) on virtual substrates. A second anisotropy, considerably smaller in strength, originates a [010] or [100] easy axis: it persists at large thickness (up to 60 Fe layers) and is essentially associated to bulk properties. However, this is not an intrinsic property, being related to the sample preparation conditions, i.e., substrate sputtering at oblique incidence for cleaning and Fe deposition at oblique incidence. The uniaxial easy axis is always perpendicular to the incidence plane, either of the Fe atoms flux or the ion beam, with a larger effect of deposition conditions with respect to sputtering. Our results give evidence of a strong correlation between morphology and magnetism in Fe Ge Si1-x Gex Si (001) and Fe Ge (001) films, opening the way to the engineering of magnetic properties via the control of the preparation conditions. {\textcopyright} 2006 The American Physical Society.},
author = {Cantoni, M. and Riva, M. and Bertacco, R. and Ciccacci, F.},
doi = {10.1103/PhysRevB.74.134415},
issn = {10980121},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {13},
title = {{Uniaxial magnetic anisotropies in Fe films on single crystal and virtual Ge(001) substrates studied with spin polarized inverse photoemission and MOKE}},
volume = {74},
year = {2006}
}

2005

  • [DOI] A. Brambilla, L. Duò, M. Cantoni, M. Riva, R. Bertacco, M. Portalupi, and F. Ciccacci, "Onset of ferromagnetism in ultrathin Fe films on semiconductors," Solid State Communications, vol. 135, iss. 3, 2005.
    [Bibtex] 
    @article{Brambilla2005,
abstract = {Very thin Fe films have been grown by molecular beam epitaxy on Ge(001), GaAs(001) and ZnSe(001) substrates, under identical preparation conditions. The electronic and magnetic properties of such interfaces have been studied, as a function of the Fe thickness, by means of spin resolved inverse photoemission. From the spin dependence of Fe empty states, we observe the onset of room temperature ferromagnetism to occur at a Fe thickness as low as three monolayers (ML) for Fe/Ge, while 5 and 8 ML have been found for Fe/GaAs and Fe/ZnSe, respectively. {\textcopyright} 2005 Elsevier Ltd. All rights reserved.},
author = {Brambilla, A. and Du{\`{o}}, L. and Cantoni, M. and Riva, M. and Bertacco, R. and Portalupi, M. and Ciccacci, F.},
doi = {10.1016/j.ssc.2005.04.020},
issn = {00381098},
journal = {Solid State Communications},
keywords = {A. Magnetic films and multilayers,A. Semiconductors,A. Surfaces and interfaces,D. Electronic band structure},
number = {3},
title = {{Onset of ferromagnetism in ultrathin Fe films on semiconductors}},
volume = {135},
year = {2005}
}
  • [DOI] U. Lüders, M. Bibes, J. -F. Bobo, M. Cantoni, R. Bertacco, and J. Fontcuberta, "Enhanced magnetic moment and conductive behavior in Ni Fe2 O4 spinel ultrathin films," Physical Review B - Condensed Matter and Materials Physics, vol. 71, iss. 13, 2005.
    [Bibtex] 
    @article{Luders2005,
abstract = {Bulk Ni Fe2 O4 is an insulating ferrimagnet. Here, we report on the epitaxial growth of spinel Ni Fe2 O4 ultrathin films onto SrTi O3 single crystals. We will show that-under appropriate growth conditions-epitaxial stabilization leads to the formation of a spinel phase with magnetic and electrical properties that radically differ from those of the bulk material: an enhanced magnetic moment (MS) -about 250% larger-and a metallic character. A systematic study of the thickness dependence of MS allows us to conclude that its enhanced value is due to an anomalous distribution of the Fe and Ni cations among the A and B sites of the spinel structure resulting from the off-equilibrium growth conditions and to interface effects. The relevance of these findings for spinel- and, more generally, oxide-based heterostructures is discussed. We will argue that this novel material could be an alternative ferromagetic-metallic electrode in magnetic tunnel junctions. {\textcopyright} 2005 The American Physical Society.},
author = {L{\"{u}}ders, U. and Bibes, M. and Bobo, J.-F. and Cantoni, M. and Bertacco, R. and Fontcuberta, J.},
doi = {10.1103/PhysRevB.71.134419},
issn = {10980121},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {13},
title = {{Enhanced magnetic moment and conductive behavior in Ni Fe2 O4 spinel ultrathin films}},
volume = {71},
year = {2005}
}
  • [DOI] M. Cantoni, M. Riva, G. Isella, R. Bertacco, and F. Ciccacci, "Fe thin films grown on single-crystal and virtual Ge(001) substrates," Journal of Applied Physics, vol. 97, iss. 9, 2005.
    [Bibtex] 
    @article{Cantoni2005,
abstract = {Thin Fe films have been epitaxially grown at room temperature on standard single-crystal Ge(001) substrates and virtual GeSi (001) substrates. Their structural, magnetic, and electronic properties have been investigated in situ by spin-polarized inverse photoemission, x-ray photoemission spectroscopy, x-ray photoelectron diffraction, low-energy electron diffraction, and magneto-optical Kerr effect. In both cases Fe grows in a layer-by-layer fashion with very low Ge incorporation in the film (less than 3%) and the bcc local structure becomes evident for coverage larger than 5 ML. The onset of ferromagnetism appears definitively at 3 ML, while the coercive field and the spin polarization of unoccupied Fe states increase with thickness up to 30 ML. The overall behavior is very similar in the case of standard and virtual substrates, so the latter can be employed for growing high-quality FeGe interfaces. {\textcopyright} 2005 American Institute of Physics.},
author = {Cantoni, M. and Riva, M. and Isella, G. and Bertacco, R. and Ciccacci, F.},
doi = {10.1063/1.1887836},
issn = {00218979},
journal = {Journal of Applied Physics},
number = {9},
title = {{Fe thin films grown on single-crystal and virtual Ge(001) substrates}},
volume = {97},
year = {2005}
}
  • [DOI] R. Bertacco, M. Riva, M. Cantoni, L. Signorini, and F. Ciccacci, "Epitaxial la2/3Sr1/3MnO3 thin films with metallic behavior above the Curie temperature," Applied Physics Letters, vol. 86, iss. 25, 2005.
    [Bibtex] 
    @article{Bertacco2005,
abstract = {Despite its half-metallic character, La2/3Sr 1/3MnO3 is currently not considered a good candidate for real spin electronic devices due to the dramatic deterioration of its spin polarization at room temperature. Using pulsed-laser deposition, we have grown thin films of La2/3Sr1/3MnO3, which display good room-temperature magnetic properties accompanied by a sizable increase of the temperature at which the metal-insulator transition takes place with respect to the Curie temperature. The persistence of the metallic character well above the Curie temperature indicates minor modifications of the electronic structure near the Fermi level, which is responsible for the half-metallicity. These films are good candidates for increasing the operating temperature of devices based on La2/3Sr1/3MnO3. {\textcopyright} 2005 American Institute of Physics.},
author = {Bertacco, R. and Riva, M. and Cantoni, M. and Signorini, L. and Ciccacci, F.},
doi = {10.1063/1.1949727},
issn = {00036951},
journal = {Applied Physics Letters},
number = {25},
title = {{Epitaxial la2/3Sr1/3MnO3 thin films with metallic behavior above the Curie temperature}},
volume = {86},
year = {2005}
}
  • [DOI] R. Bertacco, M. Cantoni, M. Riva, A. Tagliaferri, and F. Ciccacci, "Epitaxial growth and characterization of layered magnetic nanostructures," Applied Surface Science, vol. 252, iss. 5, 2005.
    [Bibtex] 
    @article{Bertacco2005a,
abstract = {We describe the construction and operation of an ultrahigh-vacuum system devoted to the study of layered magnetic nanostructures. The apparatus includes two growth chambers, where specimens nanostructured along the direction of growth (heterostructures, nanometric and subnanometric thin films and multilayers) are deposited either by molecular beam epitaxy or pulsed laser deposition, and a measurement chamber, where they are analyzed in situ by a variety of electron spectroscopies. Magnetic characterization is obtained by spin resolved inverse photoemission spectroscopy and magneto optical Kerr effect technique. Vacuum transfer towards other experimental facilities is also available. As examples of application, results from half metallic magnetic oxides, such as magnetite (Fe 3 O 4 ) and manganite (La 2/3 Sr 1/3 MnO 3 ) thin films, and ferromagnet/semiconductor interfaces (Fe/Ge(0 0 1)) are also reported. {\textcopyright} 2005 Elsevier B.V. All rights reserved.},
author = {Bertacco, R. and Cantoni, M. and Riva, M. and Tagliaferri, A. and Ciccacci, F.},
doi = {10.1016/j.apsusc.2005.03.123},
issn = {01694332},
journal = {Applied Surface Science},
keywords = {Epitaxial growth,Spin resolved electron spectroscopy,Spintronics,Thin magnetic films},
number = {5},
title = {{Epitaxial growth and characterization of layered magnetic nanostructures}},
volume = {252},
year = {2005}
}

2004

  • [DOI] R. Bertacco, M. Riva, M. Cantoni, F. Ciccacci, M. Portalupi, A. Brambilla, L. Duò, P. Vavassori, F. Gustavsson, J. -M. George, M. Marangolo, M. Eddrief, and V. H. Etgens, "Electronic, magnetic, and structural properties of the Fe/ZnSe interface," Physical Review B - Condensed Matter and Materials Physics, vol. 69, iss. 5, 2004.
    [Bibtex] 
    @article{Bertacco2004,
abstract = {The electronic, magnetic, and structural properties of Fe thin films epitaxially grown on ZnSe(001) have been investigated by spin polarized inverse photoemission, x-ray photoemission, magneto-optical Kerr effect, and scanning tunneling microscopy. Ultrathin Fe films present no magnetic remanence, while ferromagnetism develops for Fe coverage larger than 7 ML. However, even in this case, the electronic structure of empty states is quite different from that of high quality Fe(001) films. These findings are interpreted in terms of an evolution from a low coverage superparamagnetic phase towards a ferromagnetic phase typical of thicker films, whose electronic properties still remain different from those of ideal Fe(001) films. The consequences for spin-dependent transport across the Fe/ZnSe(001) interface are discussed. {\textcopyright} 2004 The American Physical Society.},
author = {Bertacco, R. and Riva, M. and Cantoni, M. and Ciccacci, F. and Portalupi, M. and Brambilla, A. and Du{\`{o}}, L. and Vavassori, P. and Gustavsson, F. and George, J.-M. and Marangolo, M. and Eddrief, M. and Etgens, V.H.},
doi = {10.1103/PhysRevB.69.054421},
issn = {1550235X},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {5},
title = {{Electronic, magnetic, and structural properties of the Fe/ZnSe interface}},
volume = {69},
year = {2004}
}
  • [DOI] M. Portalupi, R. Bertacco, M. Cantoni, A. Brambilla, M. Riva, L. Duó, and F. Ciccacci, "Electronic and magnetic properties of the Fe/ZnSe(0 01) interface," Journal of Magnetism and Magnetic Materials, vol. 272-276, iss. III, 2004.
    [Bibtex] 
    @article{Portalupi2004,
abstract = {The electronic, magnetic and structural properties of thin Fe films epitaxially grown on ZnSe(001) have been investigated by means of spin resolved inverse photoemission and low energy electron diffraction. Ultrathin Fe films grown on ZnSe(001) present no magnetic remanence, while ferromagnetism develops for coverages greater than 8 monolayers. These findings are interpreted in terms of an evolution from a low coverage superparamagnetic phase towards a ferromagnetic phase typical of thicker films. {\textcopyright} 2003 Elsevier B.V. All rights reserved.},
author = {Portalupi, M. and Bertacco, R. and Cantoni, M. and Brambilla, A. and Riva, M. and Du{\'{o}}, L. and Ciccacci, F.},
doi = {10.1016/j.jmmm.2003.12.342},
issn = {03048853},
journal = {Journal of Magnetism and Magnetic Materials},
keywords = {Ferromagnetism,Interfaces,Spintronics,Thin films,ZnSe},
number = {III},
title = {{Electronic and magnetic properties of the Fe/ZnSe(0 01) interface}},
volume = {272-276},
year = {2004}
}
  • [DOI] M. Cantoni and R. Bertacco, "High efficiency apparatus for spin polarized inverse photoemission," Review of Scientific Instruments, vol. 75, iss. 7, 2004.
    [Bibtex] 
    @article{Cantoni2004,
abstract = {A compact and efficient apparatus for spin polarized inverse photoemission coupling a spin resolved electron gun with a bandpass detector at 9.3 eV photon energy was analyzed. Some examples of application of the entire apparatus to the case of Ag(001) and Fe(001)-p(1×1)O surfaces were described. A sizable increase of the solid collection angle for photons was provided by the detector placed all around the electron gun. It was shown that the apparatus has an overall energy resolution of 0.75 eV and an efficiency of 3000 cps/$\mu$A as measured on Ag(001), three times better than the best value reported in literature.},
author = {Cantoni, M. and Bertacco, R.},
doi = {10.1063/1.1753681},
issn = {00346748},
journal = {Review of Scientific Instruments},
number = {7},
title = {{High efficiency apparatus for spin polarized inverse photoemission}},
volume = {75},
year = {2004}
}

2000

  • [DOI] M. Cantoni, M. Marseguerra, and E. Zio, "Genetic algorithms and Monte Carlo simulation for optimal plant design," Reliability Engineering and System Safety, vol. 68, iss. 1, 2000.
    [Bibtex] 
    @article{Cantoni2000,
abstract = {We present an approach to the optimal plant design (choice of system layout and components) under conflicting safety and economic constraints, based upon the coupling of a Monte Carlo evaluation of plant operation with a Genetic Algorithms-maximization procedure. The Monte Carlo simulation model provides a flexible tool, which enables one to describe relevant aspects of plant design and operation, such as standby modes and deteriorating repairs, not easily captured by analytical models. The effects of deteriorating repairs are described by means of a modified Brown-Proschan model of imperfect repair which accounts for the possibility of an increased proneness to failure of a component after a repair. The transitions of a component from standby to active, and vice versa, are simulated using a multiplicative correlation model. The genetic algorithms procedure is demanded to optimize a profit function which accounts for the plant safety and economic performance and which is evaluated, for each possible design, by the above Monte Carlo simulation. In order to avoid an overwhelming use of computer time. for each potential solution proposed by the genetic algorithm, we perform only few hundreds Monte Carlo histories and, then, exploit the fact that during the genetic algorithm population evolution, the fit chromosomes appear repeatedly many times, so that the results for the solutions of interest (i.e. the best ones) attain statistical significance.},
author = {Cantoni, M. and Marseguerra, M. and Zio, E.},
doi = {10.1016/S0951-8320(99)00080-0},
issn = {09518320},
journal = {Reliability Engineering and System Safety},
number = {1},
title = {{Genetic algorithms and Monte Carlo simulation for optimal plant design}},
volume = {68},
year = {2000}
}